Sodium:chemical element with the symbol Na and atomic number 11

Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride.Sony VAIO VGN-FW160F/E Battery

Many salts of sodium are highly soluble in water and are thus present in significant quantities in the Earth's bodies of water.

Many sodium compounds are useful, such as sodium hydroxide (lye) for soapmaking, and sodium chloride for use as a deicing agent and a nutrient. Sodium is an essential element for all animals and some plants. Sony VAIO VGN-FW170J/H Battery

In animals, sodium ions are used against potassium ions to build up charges on cell membranes, allowing transmission of nerve impulses when the charge is dissipated; hence, it is thus classified as a dietary inorganic macro-mineral.

The free metal, elemental sodium, does not occur in nature but must be prepared from sodium compounds. Sony VAIO VGN-FW180AE Battery

Elemental sodium was first isolated by Humphry Davy in 1807 by the electrolysis of sodium hydroxide. The same ion is also a component of many minerals, such as sodium nitrate.

Characteristics of the metal

At room temperature, sodium metal is soft enough that it can be cut with a knife.Sony VAIO VGN-FW180D Battery

In air, the bright silvery luster of freshly exposed sodium will rapidly tarnish. The density of alkali metals generally increases with increasing atomic number, but sodium is denser than potassium. Sodium is a fairly good conductor of heat.

Under exotic conditions, the properties of the metal change. Sony VAIO VGN-FW180E Battery

At high pressures, it becomes black at 1.5 megabar, becoming a red transparent substance at 1.9 megabar, and is predicted to become clearly transparent at 3 megabar. The high pressureallotropes are insulators and take the form of sodium electride.Sony VAIO VGN-FW180E/H Battery

Chemical properties

Compared with other alkali metals, sodium is generally less reactive than potassium and more reactive than lithium, in accordance with "periodic law": for example, their reaction in water, chlorine gas, etc.Sony VAIO VGN-FW180FU Battery

Sodium reacts exothermically with water: small pea-sized pieces will bounce across the surface of the water until they are consumed by it, whereas large pieces will explode. While sodium reacts with water at room temperature, the sodium piece melts with the heat of the reaction to form a sphere, if the reacting sodium piece is large enough. Sony VAIO VGN-FW190EBH Battery

The reaction with water produces very caustic sodium hydroxide(lye) and highly flammable hydrogen gas. These are extreme hazards. When burned in air, sodium formssodium peroxide Na2O2, or with limited oxygen, sodium oxide Na2O (unlike lithium, the nitride is not formed). If burned in oxygen under pressure, sodium superoxide NaO2 is produced.Sony VAIO VGN-FW190ECH Battery

Spectroscopy

When sodium or its compounds are introduced into a flame, they turn the flame a bright yellow color. Oneatomic spectral line of sodium vapor is the so-called D-line, which may be observed directly as the sodium flame-test line and also the major light output of low-pressuresodium lamps (these produce an unnatural yellow, rather than the peach-colored glow of high pressure lamps). Sony VAIO VGN-FW190EDH Battery

The D-line is one of the classified Fraunhofer lines observed in the visible spectrum of the Sun's electromagnetic radiation. Sodium vapor in the upper layers of the Sun creates a dark line in the emitted spectrum of electromagnetic radiation by absorbing visible light in a band of wavelengths around 589.5 nm. Sony VAIO VGN-FW190NAH Battery

This wavelength corresponds to transitions in atomic sodium in which the valence-electron transitions from a 3p to 3s electronic state. Closer examination of the visible spectrum of atomic sodium reveals that the D-line actually consists of two lines called the D1and D2lines at 589.6 nm and 589.0 nm, respectively. Sony VAIO VGN-FW190NBH Battery

This fine structure results from a spin-orbit interaction of the valence electron in the 3p electronic state. The spin-orbit interaction couples the spin angular momentum and orbital angular momentum of a 3p electron to form two states that are respectively notated as 3p(2P01/2) and 3p(2P03/2) in the LS coupling scheme. Sony VAIO VGN-FW190NCH Battery

The 3s state of the electron gives rise to a single state which is notated as 3s(2S1/2) in the LS coupling scheme. The D1-line results from an electronic transition between 3s(2S1/2) lower state and 3p(2P01/2) upper state. The D2-line results from an electronic transition between 3s(2S1/2) lower state and 3p(2P03/2) upper state.Sony VAIO VGN-FW190NDH Battery

Even closer examination of the visible spectrum of atomic sodium would reveal that the D-line actually consists of a lot more than two lines. These lines are associated with hyperfine structure of the 3p upper states and 3s lower states. Many different transitions involving visible light near 589.5 nm may occur between the different upper and lower hyperfine levels. Sony VAIO VGN-FW190NEH Battery

A practical use for lasers which work at the sodium D-line transition is to create artificial laser guide stars(artificial star-like images from sodium in the upper atmosphere) which assist in the adaptive optics for large land-based visible light telescopes.Sony VAIO VGN-FW198U/H Battery

Isotopes

Nearly twenty isotopes of sodium have been recognized, the only stable one being 23Na. Sodium has two radioactivecosmogenic isotopes which are also the two isotopes with longest half-life, 22Na, with a half-life of 2.6 years and 24Na with a half-life of 15 hours. All other isotopes have a half-life of less than one minute.Sony VAIO VGN-FW260J/B Battery

Acute neutron radiation exposure (e.g., from a nuclear criticality accident) converts some of the stable 23Na in human blood plasma to24Na. By measuring the concentration of this isotope, the neutron radiation dosage to the victim can be computed.Sony VAIO VGN-FW280J/H Battery

Compounds

Sodium compounds are of immense commercial importance, being particularly central to industries producing glass, paper, soap, andtextiles. The sodium compounds that are the most important are common salt (NaCl), soda ash (Na2CO3),Sony VAIO VGN-FW290JRB Battery

baking soda (NaHCO3), caustic soda (NaOH), sodium nitrate (NaNO3), di- and tri-sodium phosphates, sodium thiosulfate (Na2S2O3·5H2O), and borax (Na2B4O7·10H2O).

In its compounds, sodium is usually connected via ionic bonding to water and the anions. In this way, it is viewed as a weak but "hard" Lewis acid.Sony VAIO VGN-FW290JTB Battery

Aqueous solutions

Sodium tends to form water-soluble compounds, such as halides, sulfate, nitrate, carboxylates and carbonates. The main species in water are the aquo complexes [Na(H2O)n]+ where n = 4-6.

The high affinity of sodium for oxygen-based ligands is the basis of crown ethers. Sony VAIO VGN-FW290JTH Battery

Functionally related but more complex ligands are several macrolide antibiotics, which function by interfering with the transport of Na+ in the infecting organism.

Examples of sodium salts precipitating from water solution are rare, and most feature large or organic anions.Sony VAIO VGN-FW290JTW Battery

illustrative sodium salts exhibiting low solubility include sodium bismuthate (NaBiO3). Since sodium salts are so soluble in water, they are usually isolated as solids by evaporation of these aqueous solutions or by precipitation with an organic solvent. For example, 360 g of sodium chloride will dissolve in water. Sony VAIO VGN-FW355J/H Battery

The addition of ethanol to such solutions causes solid NaCl to separate (precipitate), because only 0.35 g of sodium chloride will dissolve in the alcohol.

Organosodium compounds

Many organosodium compounds have been prepared. Because of the high polarity of the C-Na bonds, they are treated sources ofcarbanions.Sony VAIO VGN-FW373J/B Battery

Some well known derivatives include sodium cyclopentadienide (NaC5H5) and trityl sodium ((C6H5)3CNa).

History

Salt has been an important commodity in human activities, as testified by the English word salary, referring tosalarium, the wafers of salt sometimes given to Roman soldiers along with their other wages.Sony VAIO VGN-FW30B Battery

In medieval Europe a compound of sodium with the Latin name of sodanum was used as a headache remedy. The name sodium probably originates from the Arabic word suda meaning headache as the headache-alleviating properties of sodium carbonate or soda were well known in early times.Sony VAIO VGN-FW50B Battery

Sodium's chemical abbreviation Na was first published by Jöns Jakob Berzelius in his system of atomic symbols (Thomas Thomson, Annals of Philosophy ) and is a contraction of the element's new Latin name natrium which refers to the Egyptian natron,the word for a natural mineral salt whose primary ingredient is hydrated sodium carbonate. Sony VAIO VGN-FW51B/W Battery

Hydrated sodium carbonate historically had several important industrial and household uses later eclipsed by soda ash,baking soda and other sodium compounds.

Although sodium (sometimes called "soda" in English) has long been recognized in compounds, the metal itself was not isolated until 1807 by Humphry Davy through the electrolysis of caustic soda.Sony VAIO VGN-FW51MF Battery

Sodium imparts an intense yellow color to flames; as early as 1860, Kirchhoff and Bunsen noted the high sensitivity of a sodium flame test, and stated in Annalen der Physik und Chemie:

In a corner of our 60 m3 room farthest away from the apparatus, we exploded 3 mg. of sodium chlorate with milk sugar while observing the nonluminous flame before the slit. Sony VAIO VGN-FW51MF/H Battery

After a while, it glowed a bright yellow and showed a strong sodium line that disappeared only after 10 minutes. From the weight of the sodium salt and the volume of air in the room, we easily calculate that one part by weight of air could not contain more than 1/20 millionth weight of sodium.Sony VAIO VGN-FW51ZF Battery

Creation

Stable forms of sodium are created in stars through nuclear fusion by fusing two carbon atoms together. This requires temperatures above 600 megakelvins, inside an evolved star with at least three solar masses.Sony VAIO VGN-FW51ZF/H Battery

Occurrence

Sodium makes up about 2.6% by weight of the Earth's crust, making it the sixth most abundant elementoverall and the most abundant alkali metal. Sodium is found in many different minerals, of which the most common is ordinary salt (sodium chloride),Sony VAIO VGN-FW52JB Battery

which occurs in vast quantities dissolved in seawater, as well as in solid deposits (halite). Others include amphibole, cryolite, soda niter, andzeolite. Owing to its high reactivity, sodium is never found in nature the metal.Sony VAIO VGN-FW54FB Battery

Nature provides many examples of insoluble sodium compounds such as the cryolite and the feldspars(aluminosilicates of sodium, potassium, and calcium). The low solubility of these species is due to the polymeric nature of the anions, such as polysilicates.Sony VAIO VGN-FW70DB Battery

Interstellar medium

Sodium is relatively abundant in stars and the D spectral lines of this element are among the most prominent in star light. Though elemental sodium has a rather high vaporization temperature, its relatively high abundance and very intense spectral lines have allowed its presence to be detected by ground telescopes and confirmed by spacecraft (Mariner 10 and MESSENGER) in the thin atmosphere of the planet Mercury. Sony VAIO VGN-FW71DB/W Battery

Commercial production of metallic sodium

Enjoying rather specialized applications, only about 100,000 tonnes/y of metallic sodium are produced annually. Metallic sodium was first produced commercially in 1855 by carbothermal reduction of sodium carbonate at 1100 °C, in what is known as the Deville process: Sony VAIO VGN-FW72JGB Battery

Na2CO3 + 2 C ? 2 Na + 3 CO

A related process based on the reduction of sodium hydroxide was developed in 1886.

Sodium is now produced commercially through the electrolysis of molten sodium chloride, based on a process patented in 1924.Sony VAIO VGN-FW73JGB Battery

This is done in a Downs Cell in which the NaCl is mixed with calcium chloride to lower the melting point below 700 °C. As calcium is less electropositive than sodium, no calcium will be formed at the anode. This method is less expensive than the previous Castner process of electrolyzing sodium hydroxide.Sony VAIO VGN-FW74FB Battery

Sodium metal in reagent-grade sold for about US$1.50/pound ($3.30/kg) in 2009 when purchased in tonne quantities. Lower purity metal sells for considerably less. The market in this metal is volatile due to the difficulty in its storage and shipping. Sony VAIO VGN-FW81HS Battery

It must be stored under a dry inert gas atmosphere or anhydrous mineral oil to prevent the formation of a surface layer of sodium oxide or sodium superoxide. These oxides can react violently in the presence of organic materials. Sodium will also burn violently when heated in air. Sony VAIO VGN-FW81NS Battery

Smaller quantities of sodium, such as a kilogram, cost far more, in the range of US$165/kg. The high cost is partially due to the expense of shipping hazardous material.

Applications

The dominant applications of sodium are for its many chemical compounds.Sony VAIO VGN-FW81S Battery

In terms of scale, the chloride, hydroxide, and carbonate are produced on megatons/y. Although not produced on comparable tonnage, many important medicine formulations are sodium or potassium is a common modification to improve bioavailability.

Soap

Most soaps are sodium salts of fatty acids. Sodium soaps are harder (higher melting) soaps than potassium soaps.[10]Sodium chloride (NaCl) is used on a massive scale for de-icing and in foods, i.e. salting food to preserve it etc.Baking soda (Sodium bicarbonate) is mainly used for cooking.Sony VAIO VGN-FW82DS Battery

Metallic sodium

Sodium in its metallic form is mainly consumed for the production of the following chemical compounds: sodium hydride(NaH, precursor to sodium borohydride), sodium amide (NaNH2 (precursor to sodium azide and indigo), triphenylphosphine (P(C6H5)3, reagent for the production ofvitamin A).Sony VAIO VGN-FW82JS Battery

In former times, the production of tetraethyllead and titanium metal were the major consumers of metallic sodium, but these technologies have been discontinued. Consequently the production of sodium declined since the 1970's.[9] Some continuing applications include:Sony VAIO VGN-FW82XS Battery

• In certain alloys to improve their structure.
• To descale metal (make its surface smooth).
• To purify molten metals. Especially where carbon, aluminium etc. cannot be used for reducing metallic compounds.Sony VAIO VGN-FW83DS Battery
• sodium vapor lamps are an efficient means of producing light from electricity and they are often used for street lighting in cities. Low-pressure sodium lamps give a distinctive yellow-orange light which consists primarily of the twin sodium D lines.Sony VAIO VGN-FW83JS Battery
• High-pressure sodium lamps give a more natural peach-colored light, composed of wavelengths spread much more widely across the spectrum.
• In organic synthesis, sodium is used as a reducing agent, for example in the Birch reduction. It is also used for preparing Na-Extract which is a major method of identification of elements present in organic compound.Sony VAIO VGN-FW83XS Battery
• In chemistry, sodium is often used either alone or with potassium in an alloy, NaK as a desiccant for drying solvents. Used with benzophenone, it forms an intense blue coloration when the solvent is dry and oxygen-free.
• The sodium fusion test uses sodium's high reactivity, low melting point, and the near-universal solubility of its compounds, to qualitatively analyze compounds.Sony VAIO VGN-FW90HS Battery

Heat exchanger

As a heat transfer fluid, sodium is found in sodium-cooled fast reactors and inside the hollow valves of high-performance internal combustion engines.

Molten sodium is used as a coolant in some types of fast neutron reactors. Sony VAIO VGN-FW90NS Battery

It has a low neutron absorption cross section, which is required to achieve a high enough neutron flux, and has excellent thermal conductivity. Its high boiling point allows the reactor to operate at ambient pressure. However, using sodium poses certain challenges. Sony VAIO VGN-FW90S Battery

The molten metal will readily burn in air and react violently with water, liberating explosive hydrogen. During reactor operation, a small amount of sodium-24 is formed as a result of neutron activation, making the coolant radioactive.

Sodium leaks and fires were a significant operational problem in the first large sodium-cooled fast reactors, causing extended shutdowns at the Monju Nuclear Power Plant and Beloyarsk Nuclear Power Plant.Sony VAIO VGN-FW91NS Battery

Where reactors need to be frequently shut down, as is the case with some research reactors, the alloy of sodium and potassium called NaK is used. It melts at ?11 °C, so cooling pipes will not freeze at room temperature. Extra precautions against coolant leaks need to be taken in case of NaK, because molten potassium will spontaneously ignite when exposed to air.Sony VAIO VGN-FW91S Battery

The phase diagram with potassium shows that the mixtures with potassium are liquid at room temperature in a wide concentration range. A compound Na2K melts at 7 °C. The eutectic mixture with a potassium content of 77 % gives a melting point at ?12.6 °C.Sony VAIO VGN-FW92DS Battery

Botany

Although sodium is not considered as important as potassium, it is considered as micronutrient in most plants as it is necessary in the metabolism of some C4 plants, e.g. Rhodes grass, amaranth, Joseph's coat, and pearl millet.Sony VAIO VGN-FW92JS Battery

Within these C4 plants, sodium is used in the regeneration of phosphoenolpyruvate (PEP) and the synthesis of chlorophyll. In addition, the presence of sodium can offset potassium requirements in many plants by substituting in several roles, such as:Sony VAIO VGN-FW93JS Battery

maintaining turgor pressure, serving as an accompanying cation in long distance transport, and aiding in stomatal opening and closing.

Increasing soil salinity, osmotic stress and sodium toxicity in plants, especially in agricultural crops, have become worldwide phenomena.Sony VAIO VGN-FW93XS Battery

High levels of sodium in the soil solution limit the plants' ability to uptake water due to decreased soil water potential and, therefore, may result in wilting of the plant. In addition, excess sodium within the cytoplasm of plant cells can lead to enzyme inhibition, which may result in symptoms such as necrosis, chlorosis, and possible plant death.Sony VAIO VGN-FW94FS Battery

To avoid such symptoms, plants have developed methods to combat high sodium levels, such as: mechanisms limiting sodium uptake by roots, compartmentalization of sodium in cell vacuoles, and control of sodium in long distance transport. Many plants store excess sodium in old plant tissue, limiting damage to new growth.Sony VAIO VGN-FW94GS Battery

Biological role

Sodium is an essential nutrient that regulates blood volume and blood pressure, "maintains the right balance of fluids in the body, transmits nerve impulses, and influences the contraction and relaxation of muscles".Sony VAIO VGN-FW94HS Battery

It is also necessary for maintaining osmotic equilibrium and the acid-base balance. The minimum physiological requirement for sodium is only 500 milligrams per day. However, according to the American Heart Association, in order to "ensure nutrient adequacy and replace sweat losses a healthy adult needs 1,500 milligrams of sodium per day" or 2/3 of a teaspoon. Sony VAIO VGN-G118CN Battery

Maintaining body fluid volume in animals

The serum sodium and urine sodium play important roles in medicine, both in the maintenance of sodium and total body fluid homeostasis, and in the diagnosis of disorders causing homeostatic disruption of salt/sodium and water balance.Sony VAIO VGN-G118GN/B Battery

In mammals, decreases in blood pressure and decreases in sodium concentration sensed within the kidney result in the production of renin, a hormone which acts in a number of ways, one of them being to act indirectly to cause the generation of aldosterone, a hormone which decreases the excretion of sodium in the urine. Sony VAIO VGN-G118GN/T Battery

As the body of the mammal retains more sodium, other osmoregulation systems which sense osmotic pressure in part from the concentration of sodium and water in the blood, act to generate antidiuretic hormone. This, in turn, causes the body to retain water, thus helping to restore the body's total amount of fluid.Sony VAIO VGN-G118TN/B Battery

There is also a counterbalancing system, which senses volume. As fluid is retained, receptors in the heart and vessels which sense distension and pressure, cause production of atrial natriuretic peptide, which is named in part for the Latin word for sodium. This hormone acts in various ways to cause the body to lose sodium in the urine.Sony VAIO VGN-G118TN/S Battery

This causes the body's osmotic balance to drop (as low concentration of sodium is sensed directly), which in turn causes the osmoregulation system to excrete the "excess" water. The net effect is to return the body's total fluid levels back toward normal.Sony VAIO VGN-G11VN/T Battery

Maintaining electric potential in animal tissues

Sodium cations are important in neuron (brain and nerve) function, and in influencing osmotic balance between cells and the interstitial fluid, with their distribution mediated in all animals (but not in all plants) by the so-called Na+/K+-ATPase pump.Sony VAIO VGN-G11VN/TC Battery

Sodium is the chief cation in fluid residing outside cells in the mammalian body (the so-called extracellular compartment), with relatively little sodium residing inside cells. The volume of extracellular fluid is typically 15liters in a 70 kg human, and the 50 grams of sodium it contains is about 90% of the body's total sodium content.Sony VAIO VGN-G11XN/B Battery

Dietary uses

The most common sodium salt, sodium chloride ('table salt' or 'common salt'), is used for seasoning and warm-climate food preservation, such as pickling and makingjerky (the high osmotic content of salt inhibits bacterial and fungal growth).Sony VAIO VGN-G1AAPS Battery

The human requirement for sodium in the diet is about 1.5 grams per day. This is less than a tenth of the sodium in many diets "seasoned to taste." Most people consume far more sodium than is physiologically needed. Low sodium intake may lead tosodium deficiency (hyponatremia).Sony VAIO VGN-G1AAPSA Battery

Persons suffering from severe dehydration caused by diarrhea, such as that by cholera, can be treated with oral rehydration therapy, in which they drink a solution of sodium chloride, potassium chloride and glucose. This simple, effective therapy saves the lives of millions of children annually in the developing world.Sony VAIO VGN-G1AAPSB Battery

US consumption and guidelines

The 2010 dietary guidelines of the United States Department of Agriculture (USDA) recommend to decrease the sodium consumption to less than 2.3 g per day (1 teaspoon of salt). Sony VAIO VGN-G1AAPSC Battery

This target is lowered to 1.5 g/day (2/3 teaspoon) for "salt sensitive populations", which includes individuals older than 51, African Americans or those who have hypertension, diabetes, or chronic kidney diseases, and comprises about 50% of the US population.Sony VAIO VGN-G1ABNS Battery

The American Heart Association (AHA) proposes to lower the upper threshold to 2 g/day by 2013 and to 1.5 g/day by 2020 for everyone.

According to the USDA, consumption of sodium in the US is disproportionately greater than the recommended intake, and AHA estimates the daily intake of sodium as 3.4 g/day. Sony VAIO VGN-G1KAP Battery

NHANES reported that in 2005–2006 the lowest consumption was by 2–5 years old females (~2.1 g/day) and the highest was for 30–39 years old males (~4.7 g/day); males consumed more than 2.3 g/day regardless of age and more than females of the same age group.Sony VAIO VGN-G1KBN Battery

Dietary sodium exposure

Dietary sodium comes from table salt, natural sources and processed foods. Processed foods contain an elevated amount of sodium, along with fast food and also foods that do not taste salty such as cheeses. Primary exposure to sodium in North America (75%) comes from highly processed foods or frozen meals.Sony VAIO VGN-G1KBNA Battery

Secondary exposure is correlated with eating at restaurants, predominately fast food chains. Tertiary exposure is experienced when individuals add table salt to their meals during preparation or after they are cooked.Sony VAIO VGN-G1LAP Battery

Thus simply removing salt shakers from dining tables will not resolve the problem of excessive sodium intake, and the cooperation of food manufacturers and restaurants to reduce the sodium content will be essential. The AHA urges food manufacturers and restaurants to reduce the salt they add to food by 50% over the next 10 years.Sony VAIO VGN-G1LBN Battery

Economic impact

Regular consumption of more than 2.3 g/day of sodium promotes such health problems as elevated blood pressure and cardiovascular disease. Excessive sodium consumption causes 9–17% of cases of hypertension. Approximately 65 million adults in the United States, and 1 billion adults throughout the world have hypertension.Sony VAIO VGN-G218LN/T Battery

Worldwide, 7.6 million premature deaths (about 13.5% of the global total) and 92 million disability adjusted life years (6.0% of the global total) can be attributed to high blood pressure. In 2010, the AHA estimated that the costs associated with hypertension and cardiovascular disease amounted to $503 billion dollars, Sony VAIO VGN-G218N/B Battery

that is people with cardiovascular disease and hypertension cost more than any other diagnostic group. AHA speculates that billions of dollars and approximately 8.5 million deaths between 2006 and 2015 could be averted globally if salt consumption was reduced in accordance with the 2010 dietary guidelines.Sony VAIO VGN-G21XP/B Battery

Precautions for metallic sodium

Care is required in handling elemental (metallic) sodium. Sodium is potentially explosive upon contact with water, producing both flammable hydrogen and causticsodium hydroxide, a corrosive substance. The powdered form may combust spontaneously in air or oxygen.Sony VAIO VGN-G2AANS Battery

Its behavior is unpredictable, and, among the alkali metals, it is usually sodium that leads to surprise fires, because lithium is not reactive enough to do it, and potassium is so reactive that chemistry students are not tempted to use it.Sony VAIO VGN-G2AAPS Battery

Disposal

Waste sodium can be safely destroyed by slow hydrolysis of samples in a ventilated cabinet. A typical procedure involves sequential treatment with large excess of isopropanol followed by ethanol and finally water to dilute the caustic product. Isopropanol reacts very slowly, generating the alkoxide and hydrogen.Sony VAIO VGN-G2AAPSA Battery

Fire extinguishing

Common fire extinguishers do not extinguish (or exacerbate) fires involving sodium. Water, of course, accelerates sodium fires, as do water-based foams. CO2 andHalon are often ineffective on sodium fires, which reignite when the extinguisher dissipates.Sony VAIO VGN-G2AAPSB Battery

Among the few materials effective on a sodium fire are Pyromet and Met-L-X. Pyromet is a NaCl/(NH4)2HPO4 mix, with flow/anti-clump agents. It smothers the fire, drains away heat, and melts to form an impermeable crust. Thus the standard dry-powder canister fire extinguisher for all classes of fires are either Met-L-X, Sony VAIO VGN-G2AAPSC Battery

which is mostly sodium chloride together with approximately 5% Saran plastic as a crust-former, and flow/anti-clumping agents. It is most commonly hand-applied, with a scoop. Other extreme fire extinguishing materials include Lith+, a graphitebased dry powder with an organophosphate flame retardant; Sony VAIO VGN-G2KAN Battery

and Na+, a Na2CO3-based material. Alternatively, plain dry sand can effectively slow down the oxygen and humidity flow to the sodium.

The renin-angiotensin system (RAS) or the renin-angiotensin-aldosterone system (RAAS) is a hormone system that regulates blood pressure and water (fluid) balance.Sony VAIO VGN-G2KANA Battery

When blood volume is low, juxtaglomerular cells in the kidneys secrete renindirectly into circulation. Plasma renin then carries out the conversion ofangiotensinogen released by the liver to angiotensin I. Angiotensin I is subsequently converted to angiotensin II by the enzyme angiotensin converting enzyme found in the lungs. Sony VAIO VGN-G2KBNA Battery

Angiotensin II is a potent vaso-active peptide which causes blood vessels to constrict, resulting in increased blood pressure. Angiotensin II also stimulates the secretion of the hormone aldosterone from theadrenal cortex. Aldosterone causes the tubules of the kidneys to increase the reabsorption of sodium and water into the blood. Sony VAIO VGN-NR160E/S Battery

This increases the volume of fluid in the body, which also increases blood pressure.

If the renin-angiotensin-aldosterone system is too active, blood pressure will be too high. There are many drugs that interrupt different steps in this system to lower blood pressure. Sony VAIO VGN-NR160E/T Battery

These drugs are one of the main ways to control high blood pressure (hypertension), heart failure, kidney failure, and harmful effects ofdiabetes.

Activation

The system can be activated when there is a loss of blood volume or a drop in blood pressure (such as in hemorrhage).Sony VAIO VGN-NR160E/W Battery

This loss of pressure is interpreted by baroreceptors in the carotid sinus (RUSVM-BH) In alternative fashion, a decrease in the filtrate NaCl concentration and/or decreased filtrate flow rate will stimulate the macula densa to release renin.Sony VAIO VGN-NR180E/S Battery

1. If the perfusion of the juxtaglomerular apparatus in the kidney's macula densa decreases, then the juxtaglomerular cells (granular cells, modified pericytes in the glomerular capillary) release the enzyme renin.
2. Renin cleaves a zymogen, an inactive peptide, called angiotensinogen, converting it into angiotensin I.Sony VAIO VGN-NR180E/T Battery
3. Angiotensin I is then converted to angiotensin II by angiotensin-converting enzyme (ACE), which was thought to be found mainly in lung capillaries. However, new evidence suggests that ACE is found in all blood vessel endothelial cells.Sony VAIO VGN-NR290E/S Battery
4. Angiotensin II is the major bioactive product of the renin-angiotensin system, binding to receptors on intraglomerular mesangial cells, causing these cells to contract along with the blood vessels surrounding them and causing the release of aldosterone from the zona glomerulosa in the adrenal cortex. Sony VAIO VGN-NR290E/T Battery
5. Angiotensin II acts as an endocrine, autocrine/paracrine, and intracrine hormone.

Effects

It is believed that angiotensin I may have some minor activity, but angiotensin II is the major bio-active product. Angiotensin II has a variety of effects on the body:Sony VAIO VGN-NR298E/S Battery

• Throughout the body, it is a potent vasoconstrictor of arterioles.
• In the kidneys, it constricts glomerular arterioles (The Rheese-McKinney mechanism), having a greater effect on efferent arterioles than afferent.Sony VAIO VGN-NR460E/L Battery
• As with most other capillary beds in the body, the constriction ofafferent arterioles increases the arteriolar resistance, raising systemic arterial blood pressure and decreasing the blood flow. However, the kidneys must continue to filter enough blood despite this drop in blood flow, necessitating mechanisms to keep glomerular blood pressure up. Sony VAIO VGN-NR460E/P Battery
• To do this, angiotensin II constricts efferent arterioles, which forces blood to build up in the glomerulus, increasing glomerular pressure. The glomerular filtration rate (GFR) is thus maintained, and blood filtration can continue despite lowered overall kidney blood flow.Sony VAIO VGN-NR498E/L Battery
• Because the filtration fraction has increased, there is less plasma fluid in the downstream peritubular capillaries. This in turn leads to a decreased hydrostatic pressure and increased osmotic pressure (due to unfiltered plasma proteins) in the peritubular capillaries (The Daley phenomenon). Sony VAIO VGN-NR498E/S Battery
• The effect of decreased hydrostatic pressure and increased osmotic pressure in the peritubular capillaries will facilitate increased reabsorption of tubular fluid.
• Angiotensin II decreases medullary blood flow through the vasa recta. This decreases the washout of NaCl and urea in the kidney medullary space. Sony VAIO VGN-NR498E/T Battery
• Thus, higher concentrations of NaCl and urea in the medulla facilitate increased absorption of tubular fluid. Furthermore, increased reabsorption of fluid into the medulla will increase passive reabsorption of sodium along the thick ascending limb of the loop of Henle.Sony VAIO VGN-NR498E/W Battery
• Angiotensin II stimulates Na+/H+ exchangers located on the apical membranes (faces the tubular lumen) of cells in the proximal tubule and thick ascending limb of the loop of Henle in addition to Na+ channels in the collecting ducts. This will ultimately lead to increased sodium reabsorption .Sony VAIO VGN-NR50 Battery
• Angiotensin II stimulates the hypertrophy of renal tubule cells, leading to further sodium reabsorption.
• In the adrenal cortex, it acts to cause the release of aldosterone. Aldosterone acts on the tubules (e.g., the distal convoluted tubules and the corticalcollecting ducts) in the kidneys, causing them to reabsorb more sodium and water from the urine.Sony VAIO VGN-NR50B Battery
• This increases blood volume and, therefore, increases blood pressure. In exchange for the reabsorbing of sodium to blood, potassium is secreted into the tubules, becomes part of urine and is excreted.
• Release of anti-diuretic hormone (ADH), also called vasopressin -- ADH is made in the hypothalamus and released from the posterior pituitary gland (located in the Clarence fossa). Sony VAIO VGN-NR51 Battery
• As its name suggests, it also exhibits vaso-constrictive properties, but its main course of action is to stimulate reabsorption of water in the kidneys. ADH also acts on the central nervous system to increase an individual's appetite for salt, and to stimulate the sensation of thirst.Sony VAIO VGN-NR51B Battery

These effects directly act in concert to increase blood pressure.

Angiotensin III

• Patil Jaspal and coworkers have shown local synthesis of Angiotensin II in neurons of sympathetic ganglia.Sony VAIO VGN-NR52 Battery
• Inhibitors of angiotensin-converting enzyme (ACE inhibitors) are often used to reduce the formation of the more potent angiotensin II. Captopril is an example of an ACE inhibitor.
• Angiotensin receptor blockers (ARBs) can be used to prevent angiotensin II from acting on angiotensin receptors.Sony VAIO VGN-NR52B Battery
• Direct renin inhibitors can also be used for hypertension. The drugs that inhibit renin are aliskiren and the investigational remikiren.
• Vaccines against angiotensin II, for example CYT006-AngQb, have been investigated. Sony VAIO VGN-NR71B Battery

Other uses of ACE

ACE cleaves a number of other peptides, and in this capacity is an important regulator of the kinin-kallikrein system.

Fetal renin-angiotensin system

In the fetus, the renin-angiotensin system is predominantly a sodium-losing system, as angiotensin II has little or no effect on aldosterone levels. Sony VAIO VGN-NR71B2 Battery

Renin levels are high in the fetus, while angiotensin II levels are significantly lower; this is due to the limited pulmonary blood flow, preventing ACE (found predominantly in the pulmonary circulation) from having its maximum effect.Sony VAIO VGN-NR72B Battery

Hypertension (HTN) or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and diastolic. Sony VAIO VGN-NS10E/S Battery

Normal blood pressure is 120/80 mm/Hg. The first figure is the systolic blood pressure, the pressure there is in the arteries when your heart is contracting. The second, or lower figure, is the diastolic blood pressure, which is the pressure in your arteries between heart beats. High blood pressure is anything above 140/90 mm/Hg. Sony VAIO VGN-NS10J/S Battery

Hypertension is the opposite of hypotension. Hypertension is classified as either primary (essential) hypertension or secondary hypertension; about 90–95% of cases are categorized as "primary hypertension," which means high blood pressure with no obvious medical cause.Sony VAIO VGN-NS10L/S Battery

The remaining 5–10% of cases (Secondary hypertension) are caused by other conditions that affect the kidneys, arteries, heart or endocrine system.

Persistent hypertension is one of the risk factors for stroke, myocardial infarction, heart failure and arterial aneurysm, and is a leading cause of chronic kidney failure.Sony VAIO VGN-NS110E/L Battery

Moderate elevation of arterial blood pressure leads to shortened life expectancy. Dietary and lifestyle changes can improve blood pressure control and decrease the risk of associated health complications, although drug treatment may prove necessary in patients for whom lifestyle changes prove ineffective or insufficient.Sony VAIO VGN-NS110E/S Battery

Blood pressure is usually classified based on the systolic and diastolic blood pressures. Systolic blood pressure is the blood pressure in vessels during a heart beat. Diastolic blood pressure is the pressure between heartbeats. A systolic or the diastolic blood pressure measurement higher than the accepted normal values for the age of the individual is classified as prehypertension or hypertension.Sony VAIO VGN-NS110E/W Battery

Hypertension has several sub-classifications, including hypertension stage I, hypertension stage II, and isolated systolic hypertension. Isolated systolic hypertension refers to elevated systolic pressure with normal diastolic pressure and is common in the elderly. Sony VAIO VGN-NS115N/S Battery

These classifications are made after averaging a patient's resting blood pressure readings taken on two or more office visits. Individuals older than 50 years are classified as having hypertension if their blood pressure is consistently at least 140 mmHg systolic or 90 mmHg diastolic.Sony VAIO VGN-NS11ER/S Battery

Patients with blood pressures higher than 130/80 mmHg with concomitant presence of diabetes mellitus or kidney disease require further treatment.

Hypertension is also classified as resistant if medications do not reduce blood pressure to normal levels.Sony VAIO VGN-NS11E/S Battery

Exercise hypertension is an excessively high elevation in blood pressure during exercise. The range considered normal for systolic values during exercise is between 200 and 230 mm Hg. Exercise hypertension may indicate that an individual is at risk for developing hypertension at rest.Sony VAIO VGN-NS11J/S Battery

Signs and symptoms

Mild to moderate essential hypertension is usually asymptomatic.

Accelerated hypertension is associated with headache, drowsiness, confusion, vision disorders, nausea, and vomiting. These symptoms are collectively calledhypertensive encephalopathy.Sony VAIO VGN-NS11L/S Battery

Hypertensive encephalopathy is caused by severe small blood vessel congestion and brain swelling, which is reversible if blood pressure is lowered.

Secondary hypertension

Some additional signs and symptoms suggest that the hypertension is caused by disorders in hormone regulation. Sony VAIO VGN-NS11MR/S Battery

Hypertension combined with obesity distributed on the trunk of the body, accumulated fat on the back of the neck ('buffalo hump'), wide purple marks on the abdomen (abdominal striae), or the recent onset of diabetes suggests that an individual has a hormone disorder known as Cushing's syndrome. Sony VAIO VGN-NS11M/S Battery

Hypertension caused by other hormone disorders such as hyperthyroidism,hypothyroidism, or growth hormone excess will be accompanied by additional symptoms specific to these disorders. For example, hyperthyrodism can cause weight loss,tremors, heart rate abnormalities, reddening of the palms, and increased sweating.Sony VAIO VGN-NS11SR/S Battery

Signs and symptoms associated with growth hormone excess include coarsening of facial features, protrusion of the lower jaw, enlargement of the tongue, excessive hair growth, darkening of the skin color, and excessive sweating. . Sony VAIO VGN-NS11S/S Battery

Other hormone disorders like hyperaldosteronism may cause less specific symptoms such as numbness, excessive urination, excessive sweating, electrolyte imbalances and dehydration, and elevated blood alkalinity. and also cause mental pressure.Sony VAIO VGN-NS11ZR/S Battery

In pregnancy

Hypertension in pregnant women is one symptom of pre-eclampsia. Pre-eclampsia can progress to a life-threatening condition called eclampsia, which is the development of protein in the urine, generalized swelling, and severe seizures.Sony VAIO VGN-NS11Z/S Battery

Other symptoms indicating that brain function is becoming impaired may precede these seizures such as nausea, vomiting, headaches, and vision loss.

In addition, the systemic vascular resistance and blood pressure decrease during pregnancy. Sony VAIO VGN-NS12M/S Battery

The body must compensate by increasing cardiac output and blood volume to provide sufficient circulation in the utero-placental arterial bed.

In children

Some signs and symptoms are especially important in newborns and infants such as failure to thrive, seizures, irritability, lack of energy, and difficulty breathing.Sony VAIO VGN-NS12M/W Battery

In children, hypertension can cause headache, fatigue, blurred vision, nosebleeds, and facial paralysis.

Even with the above clinical symptoms, the true incidence of pediatric hypertension is not known. In adults, hypertension has been defined due to the adverse effects caused by hypertension. Sony VAIO VGN-NS12S/S Battery

However, in children, similar studies have not been performed thoroughly to link any adverse effects with the increase in blood pressure. Therefore, the prevalence of pediatric hypertension remains unknown due to the lack of scientific knowledge. Sony VAIO VGN-NS21M/P Battery

Essential hypertension

Essential hypertension is the most prevalent hypertension type, affecting 90–95% of hypertensive patients. Although no direct cause has been identified, there are many factors such as sedentary lifestyle, smoking, stress, visceral obesity, potassium deficiency (hypokalemia),Sony VAIO VGN-NS21M/W Battery

obesity (more than 85% of cases occur in those with a body mass index greater than 25), salt (sodium) sensitivity, alcohol intake, and vitamin D deficiency that increase the risk of developing hypertension. Risk also increases with aging, some inherited genetic mutations, and having a family history of hypertension.Sony VAIO VGN-NS21S/S Battery

An elevated level of renin, a hormone secreted by the kidney, is another risk factor, as is sympathetic nervous system overactivity. Insulin resistance, which is a component of syndrome X (or the metabolic syndrome), is also thought to contribute to hypertension.Sony VAIO VGN-NS21S/W Battery

Recent studies have implicated low birth weight as a risk factor for adult essential hypertension.

Secondary hypertension

Secondary hypertension by definition results from an identifiable cause. This type is important to recognize since it's treated differently to essential hypertension, by treating the underlying cause of the elevated blood pressure. Sony VAIO VGN-NS21Z/S Battery

Hypertension results in the compromise or imbalance of the pathophysiological mechanisms, such as the hormone-regulating endocrine system, that regulate blood plasma volume and heart function. Many conditions cause hypertension. Some are common, well-recognized secondary causes such as renovascular hypertension and Cushing's syndrome,Sony VAIO VGN-NS31M/P Battery

which is a condition where the adrenal glands overproduce the hormone cortisol. Hypertension is also caused by other conditions that cause hormone changes, such as hyperthyroidism, hypothyroidism, and certain tumors of the adrenal medulla (e.g., pheochromocytoma). Sony VAIO VGN-NS31M/W Battery

Other common causes of secondary hypertension include kidney disease, obesity/metabolic disorder, pre-eclampsia during pregnancy, the congenital defect known as coarctation of the aorta, and certain prescription and illegal drugs.Sony VAIO VGN-NS31S/S Battery

Pathophysiology

Most of the mechanisms associated with secondary hypertension are generally fully understood. However, those associated with essential (primary) hypertension are far less understood.Sony VAIO VGN-NS31Z/P Battery

What is known is that cardiac outputis raised early in the disease course, with total peripheral resistance (TPR) normal; over time cardiac output drops to normal levels but TPR is increased. Three theories have been proposed to explain this:Sony VAIO VGN-NS31Z/S Battery

• Inability of the kidneys to excrete sodium, resulting in natriuretic factors such as Atrial Natriuretic Factor being secreted to promote salt excretion with the side effect of raising total peripheral resistance.
• An overactive Renin-angiotensin system leads to vasoconstriction and retention of sodium and water. The increase in blood volume plus vasoconstriction leads to hypertension.Sony VAIO VGN-NS31Z/W Battery
• An overactive sympathetic nervous system, leading to increased stress responses.

It is also known that hypertension is highly heritable and polygenic (caused by more than one gene) and a few candidate genes have been postulated in the etiology of this condition.Sony VAIO VGN-NS38M/P Battery

Recently, work related to the association between essential hypertension and sustained endothelial damage has gained popularity among hypertension scientists. It remains unclear, however, whether endothelial changes precede the development of hypertension or whether such changes are mainly due to longstanding elevated blood pressures.Sony VAIO VGN-NS38M/W Battery

Diagnosis

Hypertension is generally diagnosed on the basis of a persistently high blood pressure. Usually this requires three separate sphygmomanometer measurements at least one week apart (see figure). Diagnosis often entails three separate visits to the physician's office.Sony VAIO VGN-NS130E/L Battery

Initial assessment of the hypertensive patient should include a complete history and physical examination. Exceptionally, if the elevation is extreme, or if symptoms of organ damage are present, then a diagnosis may be made and treatment started immediately.Sony VAIO VGN-NS130E/S Battery

Once the diagnosis of hypertension has been made, physicians will attempt to identify the underlying cause based on risk factors and other symptoms, if present.Secondary hypertension is more common in preadolescent children, with most cases caused by renal disease.Sony VAIO VGN-NS130E/W Battery

Primary or essential hypertension is more common in adolescents and has multiple risk factors, including obesity and a family history of hypertension.Laboratory tests can also be performed to identify possible causes of secondary hypertension, and to determine whether hypertension has caused damage to the heart, eyes, and kidneys. Sony VAIO VGN-NS140E/L Battery

Additional tests for diabetes and highcholesterol levels are usually performed because these conditions are additional risk factors for the development of heart disease and require treatment. Typical tests are classified as follows:

Creatinine (renal function) testing is done to assess the presence of kidney disease,Sony VAIO VGN-NS140E/S Battery

which can be either the cause or the result of hypertension. In addition, creatinine testing provides a baseline measurement of kidney function that can be used to monitor for side effects of certain antihypertensive drugs on kidney function. Additionally, testing of urine samples for protein is used as a secondary indicator of kidney disease. Sony VAIO VGN-NS140E/W Battery

Glucose testing is done to determine if diabetes mellitus is present. Electrocardiogram (EKG/ECG) testing is done to check for evidence that the heart is under strain from high blood pressure. It may also show whether there is thickening of the heart muscle (left ventricular hypertrophy) or whether the heart has experienced a prior minor disturbance such as a silent heart attack. Sony VAIO VGN-NS190J/L Battery

A chest X-ray may be performed to look for signs of heart enlargement or damage to heart tissue.

Prevention

The degree to which hypertension can be prevented depends on a number of features including current blood pressure level, sodium/potassium balance,Sony VAIO VGN-NS190J/S Battery

detection and omission of environmental toxins, changes in end/target organs (retina, kidney, heart, among others), risk factors for cardiovascular diseases and the age at diagnosis of prehypertension or at risk for hypertension. A prolonged assessment that involves repeated blood pressure measurements provides the most accurate blood pressure level assessment. Sony VAIO VGN-NS190J/W Battery

Following this, lifestyle changes are recommended to lower blood pressure, before the initiation of prescription drug therapy. According to the British Hypertension Society, the process of managing prehypertension includes lifestyle changes such as the following:Sony VAIO VGN-NS235J/L Battery

• Weight reduction and regular aerobic exercise (e.g., walking): Regular exercise improves blood flow and helps to reduce the resting heart rate and blood pressure.
• Reduce dietary sugar Sony VAIO VGN-NS235J/P Battery
• Reduce sodium (salt) in the body by disuse of condiment sodium and the adoption of a high potassium diet which rids the renal system of excess sodium. Many people use potassium chloride salt substitute to reduce their salt intake.
• Additional dietary changes beneficial to reducing blood pressure include the DASH diet (dietary approachesSony VAIO VGN-NS235J/S Battery
• to stop hypertension) which is rich in fruits and vegetables and low-fat or fat-free dairy products. Research sponsored by the National Heart, Lung, and Blood Institute[52] showed this diet to be effective. In addition, an increase in dietary potassium, which offsets the effect of sodium has been shown highly effective in reducing blood pressure.Sony VAIO VGN-NS235J/W Battery
• Discontinuing tobacco use and alcohol consumption has been shown to lower blood pressure. The exact mechanisms are not fully understood, but blood pressure (especially systolic) always transiently increases following alcohol or nicotine consumption. Sony VAIO VGN-NS240E/L Battery
• Abstaining from cigarette smoking reduces the risks of stroke and heart attack associated with hypertension.
• Vasodialators such as niacin.
• Limiting alcohol intake to less than 2 standard drinks per day can reduce systolic blood pressure by between 2-4mmHg.Sony VAIO VGN-NS290J/L Battery
• Reducing stress, for example with relaxation therapy, such as meditation and other mindbody relaxation techniques, by reducing environmental stress such ashigh sound levels and over-illumination can also lower blood pressure. Sony VAIO VGN-NS290J/S Battery
• Jacobson's Progressive Muscle Relaxation and biofeedback are also beneficial, such as device-guided paced breathing, although meta-analysis suggests it is not effective unless combined with other relaxation techniques.
• Increasing omega 3 fatty acids can help lower hypertension. Sony VAIO VGN-NS50B/L Battery
• Fish oil is shown to lower blood pressure in hypertensive individuals. The fish oil may increase sodium and water excretion.
• Caffeine raises blood pressure.
• Theobromine lowers blood pressure through its actions as both a vasodilator and a diuretic, and has been used to treat high blood pressure.Sony VAIO VGN-NS50B/W Battery

Lifestyle modifications

The first line of treatment for hypertension; which are the same as the recommended preventative lifestyle changes include:

• Dietary changes
• Physical exercise
• Weight loss Sony VAIO VGN-NS51B/L Battery

These have all been shown to significantly reduce blood pressure in people with hypertension.If hypertension is high enough to justify immediate use of medications, lifestyle changes are still recommended in conjunction with medication. Sony VAIO VGN-NS51B/P Battery

Drug prescription should take into account the patient's absolute cardiovascular risk (including risk of myocardial infarction and stroke) as well as blood pressure readings, in order to gain a more accurate picture of the patient's cardiovascular profile.Sony VAIO VGN-NS51B/W Battery

Different programs aimed to reduce psychological stress such as biofeedback, relaxation or meditation are advertised to reduce hypertension. However, in general claims of efficacy are not supported by scientific studies, which have been in general of low quality.Sony VAIO VGN-NS52JB/L Battery

Regarding dietary changes, a low sodium diet is beneficial; A Cochrane review published in 2008 concluded that a long term (more than 4 weeks) low sodium diet inCaucasians has a useful effect to reduce blood pressure, both in people with hypertension and in people with normal blood pressure.Sony VAIO VGN-NS52JB/P Battery

Also, the DASH diet (Dietary Approaches to Stop Hypertension) is a diet promoted by the National Heart, Lung, and Blood Institute (part of the NIH, a United States government organization) to control hypertension. A major feature of the plan is limiting intake of sodium,Sony VAIO VGN-NS52JB/W Battery

and it also generally encourages the consumption of nuts, whole grains, fish, poultry, fruits and vegetables while lowering the consumption of red meats, sweets, and sugar. It is also "rich in potassium, magnesium, and calcium, as well asprotein".Sony VAIO VGN-NS70B/W Battery

Medications

Several classes of medications, collectively referred to as antihypertensive drugs, are currently available for treating hypertension. Reduction of the blood pressure by 5 mmHg can decrease the risk of stroke by 34%, of ischaemic heart disease by 21%, and reduce the likelihood of dementia, heart failure, and mortalityfrom cardiovascular disease.Sony VAIO VGN-NS71B/W Battery

The aim of treatment should be to reduce blood pressure to <140/90 mmHg for most individuals, and lower for individuals with diabetes or kidney disease (some medical professionals recommend keeping levels below 120/80 mmHg). If the blood pressure goal is not met, a change in treatment should be made as therapeutic inertia is a clear impediment to blood pressure control.Sony VAIO VGN-NS72JB/W Battery

Comorbidity also plays a role in determining target blood pressure, with lower BP targets applying to patients with end-organ damage or proteinuria.

The first line antihypertensive supported by the best evidence is a low dose thiazide-based diuretic.Sony VAIO VGN-NS90HS Battery

Often multiple medications are needed to be combined to achieve the goal blood pressure. Commonly used prescription drugs include: ACE inhibitors, alpha blockers, angiotensin II receptor antagonists, beta blockers, calcium channel blockers, diuretics (e.g. hydrochlorothiazide),Sony VAIO VGN-NS92JS Battery

direct renin inhibitors and Glyceryl trinitrates which has the activity of vasodilation, thus controlling high blood pressure.

Some examples of common combined prescription drug include:

• A fixed combination of an ACE inhibitor and a calcium channel blocker. Sony VAIO VGN-NS92XS Battery
• One example of this is the combination of perindopril and amlodipine, the efficacy of which has been demonstrated in individuals with glucose intolerance or metabolic syndrome.
• A fixed combination of a diuretic and an angiotensin blocker - ARB. Sony VAIO VGN-NW11S/S Battery

Combinations of an ACE-inhibitor or angiotensin II–receptor antagonist, a diuretic and an NSAID (including selective COX-2 inhibitors and non-prescribed drugs such as ibuprofen) should be avoided whenever possible due to a high documented risk of acute renal failure. Sony VAIO VGN-NW11S/T Battery

The combination is known colloquially as a "triple whammy" in the Australian health industry.

In the elderly

Treating moderate to severe high blood pressure decreases death rates in those under 80 years of age. In those over 80 years old there was a decrease inmorbidity but no decrease in mortality.Sony VAIO VGN-NW11Z/S Battery

The recommended BP goal is <140/90 mm Hg with thiazide diuretics being the first line medication.

Resistant

Guidelines for treating resistant hypertension have been published in the UK and US.

Hypertension is the most important risk factor for death in industrialized countries.Sony VAIO VGN-NW11Z/T Battery

It increases hardening of the arteries thus predisposes individuals to heart disease, peripheral vascular disease, and strokes. Types of heart disease that may occur include: myocardial infarction, heart failure, and left ventricular hypertrophy Other complications include:Sony VAIO VGN-NW21EF/S Battery

• Hypertensive retinopathy
• Hypertensive nephropathy
• If blood pressure is very high hypertensive encephalopathy may result. Sony VAIO VGN-NW21JF Battery
• Silent stroke is a type of stroke (infarct) that does not have any outward symptoms (asymptomatic), and the patient is typically unaware they have suffered a stroke. Despite not causing identifiable symptoms a silent stroke still causes damage to the brain, and places the patient at increased risk for a major stroke in the future.Sony VAIO VGN-NW21MF Battery
• Hypertension is the major treatable risk factor associated with silent stokes.

Epidemiology

In the year 2000 it is estimated that nearly one billion people or ~26% of the adult population had hypertension worldwide. Sony VAIO VGN-NW21MF/W Battery

It was common in both developed (333 million ) and undeveloped (639 million) countries.[93] However rates vary markedly in different regions with rates as low as 3.4% (men) and 6.8% (women) in rural India and as high as 68.9% (men) and 72.5% (women) in Poland. Sony VAIO VGN-NW21ZF Battery

In 1995 it is estimated that 43 million people in the United States had hypertension or were taking antihypertensive medication, almost 24% of the adult population. The prevalence of hypertension in the United States is increasing and reached 29% in 2004.Sony VAIO VGN-NW31EF/W Battery

It is more common in blacks and native Americans and less in whites and Mexican Americans, rates increase with age, and is greater in the southeastern United States. Hypertension is more prevalent in men (though menopause tends to decrease this difference) and those of low socioeconomic status.Sony VAIO VGN-NW31JF Battery

Over 90–95% of adult hypertension is essential hypertension. One of the most common causes of secondary hypertension is primary aldosteronism.The incidenceof exercise hypertension is reported to range from 1–10%.Sony VAIO VGN-NW320F/B Battery

In children

The prevalence of high blood pressure in the young is increasing. Most childhood hypertension, particularly in preadolescents, is secondary to an underlying disorder. Kidney disease is the most common (60–70%) cause of hypertension in children. Adolescents usually have primary or essential hypertension, which accounts for 85–95% of cases.Sony VAIO VGN-NW320F/TC Battery

History

Some cite the writings of Sushruta in the 6th century BC as being the first mention of symptoms like those of hypertension. Others propose even earlier descriptions dating as far as 2600 BCE. Main treatment for what was called the "hard pulse disease" consisted in reducing the quantity of blood in a subject by the sectioning of veins or the application of leeches.Sony VAIO VGN-NW35E Battery

Well known individuals such as The Yellow Emperor of China, Cornelius Celsus, Galen, and Hipocrates advocated such treatments.

Our modern understanding of hypertension began with the work of physician William Harvey (1578–1657), who was the first to describe correctly the systemic circulation of blood being pumped around the body by the heart in his book "De motu cordis". Sony VAIO VGN-NW380F/S Battery

The basis for measuring blood pressure were established by Stephen Hales in 1733. Initial descriptions of hypertension as a disease came among others from Thomas Young in 1808 and specially Richard Bright in 1836.The first ever elevated blood pressure in a patient without kidney disease was reported by Frederick Mahomed (1849–1884).Sony VAIO VGN-NW380F/T Battery

It was not until 1904 that sodium restriction was advocated while a rice diet was popularized around 1940.

Studies in the 1920s demonstrated the public health impact of untreated high blood pressure; treatment options were limited at the time, and deaths from malignant hypertension and its complications were common. Sony VAIO VGN-NW50JB Battery

A prominent victim of severe hypertension leading to cerebral hemorrhage was Franklin D. Roosevelt (1882–1945). The Framingham Heart Study added to the epidemiological understanding of hypertension and its relationship with coronary artery disease. Sony VAIO VGN-NW51FB/N Battery

The National Institutes of Health also sponsored other population studies, which additionally showed that African Americans had a higher burden of hypertension and its complications. Before pharmacological treatment for hypertension became possible, three treatment modalities were used,Sony VAIO VGN-NW51FB/W Battery

all with numerous side-effects: strict sodium restriction, sympathectomy (surgical ablation of parts of the sympathetic nervous system), and pyrogen therapy (injection of substances that caused a fever, indirectly reducing blood pressure).

The first chemical for hypertension, sodium thiocyanate, was used in 1900 but had many side effects and was unpopular.Sony VAIO VGN-NW70JB Battery

Several other agents were developed after the Second World War, the most popular and reasonably effective of which were tetramethylammonium chloride and its derivative hexamethonium, hydralazine andreserpine (derived from the medicinal plant Rauwolfia serpentina). Sony VAIO VGN-NW71FB/N Battery

A randomized controlled trial sponsored by the Veterans Administration using these drugs had to be stopped early because those not receiving treatment were developing more complications and it was deemed unethical to withhold treatment from them. Sony VAIO VGN-NW71FB/W Battery

These studies prompted public health campaigns to increase public awareness of hypertension and the advice to get blood pressure measured and treated. These measures appear to have contributed at least in part of the observed 50% fall in stroke and ischemic heart disease between 1972 and 1994.Sony VAIO VGN-NW91FS Battery

A major breakthrough was achieved with the discovery of the first well-tolerated orally available agents. The first was chlorothiazide, the first thiazide and developed from the antibiotic sulfanilamide, which became available in 1958; ] it increased salt excretion while preventing fluid accumulation. Sony VAIO VGN-NW91GS Battery

In 1975, theLasker Special Public Health Award was awarded to the team that developed chlorothiazide. The British physician James W. Black developed beta blockers in the early 1960s; these were initially used for angina, but turned out to lower blood pressure.Sony VAIO VGN-NW91VS Battery

Black received the 1976 Lasker Award and in 1988 the Nobel Prize in Physiology or Medicine for his discovery. The next class of antihypertensives to be discovered was that of the calcium channel blockers. The first member wasverapamil, a derivative of papaverine that was initially thought to be a beta blocker and used for angina,Sony VAIO VGN-SR11M Battery

but then turned out to have a different mode of action and was shown to lower blood pressure.ACE inhibitors were developed through rational drug design; the renin-angiotensin system was known to play an important role in blood pressure regulation, and snake venom from Bothrops jararaca could lower blood pressure through inhibition of ACE. Sony VAIO VGN-SR11MR Battery

In 1977 captopril, an orally active agent, was described; this led to the development of a number of other ACE inhibitors.

Economics

The National Heart, Lung, and Blood Institute (NHLBI) estimated in 2002 that hypertension cost the United States $47.2 billion.Sony VAIO VGN-SR140D Battery

High blood pressure is the most common chronic medical problem prompting visits to primary health care providers, yet it is estimated that only 34% of the 50 million American adults with hypertension have their blood pressure controlled to a level of <140/90 mm Hg.Sony VAIO VGN-SR140D/B Battery

Thus, about two thirds of Americans with hypertension are at increased risk for heart disease. The medical, economic, and human costs of untreated and inadequately controlled high blood pressure are enormous. Adequate management of hypertension can be hampered by inadequacies in the diagnosis, treatment, and/or control of high blood pressure.Sony VAIO VGN-SR140D/P Battery

Health care providers face many obstacles to achieving blood pressure control from their patients, including resistance to taking multiple medications to reach blood pressure goals. Patients also face the challenges of adhering to medicine schedules and making lifestyle changes. Sony VAIO VGN-SR140D/S Battery

Nonetheless, the achievement of blood pressure goals is possible, and most importantly, lowering blood pressure significantly reduces the risk of death due to heart disease, the development of other debilitating conditions, and the cost associated with advanced medical care.,Sony VAIO VGN-SR140E Battery

Awareness

The World Health Organization attributes hypertension, or high blood pressure, as the leading cause of cardiovascular mortality.The World Hypertension League (WHL), an umbrella organization of 85 national hypertension societies and leagues, recognized that more than 50% of the hypertensive population worldwide are unaware of their condition.Sony VAIO VGN-SR140E/B Battery

To address this problem, the WHL initiated a global awareness campaign on hypertension in 2005 and dedicated May 17 of each year as World Hypertension Day (WHD). Over the past three years, more national societies have been engaging in WHD and have been innovative in their activities to get the message to the public. Sony VAIO VGN-SR140E/P Battery

In 2007, there was record participation from 47 member countries of the WHL. During the week of WHD, all these countries – in partnership with their local governments, professional societies, nongovernmental organizations and private industries – promoted hypertension awareness among the public through several media and public rallies.Sony VAIO VGN-SR140E/S Battery

Using mass mediasuch as Internet and television, the message reached more than 250 million people. As the momentum picks up year after year, the WHL is confident that almost all the estimated 1.5 billion people affected by elevated blood pressure can be reached.Sony VAIO VGN-SR140N/S Battery,Sony VAIO VGN-SR165E/B Battery,Sony VAIO VGN-SR165E/P Battery,Sony VAIO VGN-SR165E/S Battery,Sony VAIO VGN-SR190EBJ Battery,Sony VAIO VGN-SR190EBQ Battery