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Urine

Urine

Overview
Urine is a liquid waste product of the body secreted by the kidney
Kidney
The kidneys are paired organs, which have the production of urine as their primary function. Kidneys are seen in many types of animals, including vertebrates and some invertebrates. They are part of the urinary system, but have several secondary functions concerned with homeostatic functions. ...

s by a process of filtration from blood
Blood
Blood is a specialized bodily fluid that delivers necessary substances to the body's cells — such as nutrients and oxygen — and transports waste products away from those same cells....

 called urination
Urination
Urination, also known as micturition, voiding, peeing, and more rarely, emiction, is the process of disposing of urine from the urinary bladder through the urethra to the outside of the body. In healthy humans, the process of urination is under voluntary control; in infants and individuals with...

 and excreted through the urethra
Urethra
In anatomy, the urethra is a tube which connects the urinary bladder to the outside of the body. The urethra has an excretory function in both sexes to pass urine to the outside, and also a reproductive function in the male, as a passage for semen.The external urethral sphincter is a striated...

. Cellular metabolism generates numerous waste compounds, many rich in nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N and atomic number 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions, constituting 78% by volume of Earth's atmosphere.Many industrially important...

, that require elimination from the bloodstream. This waste is eventually expelled from the body in a process known as micturition, the primary method for excreting water-soluble chemicals from the body.
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Encyclopedia
Urine is a liquid waste product of the body secreted by the kidney
Kidney
The kidneys are paired organs, which have the production of urine as their primary function. Kidneys are seen in many types of animals, including vertebrates and some invertebrates. They are part of the urinary system, but have several secondary functions concerned with homeostatic functions. ...

s by a process of filtration from blood
Blood
Blood is a specialized bodily fluid that delivers necessary substances to the body's cells — such as nutrients and oxygen — and transports waste products away from those same cells....

 called urination
Urination
Urination, also known as micturition, voiding, peeing, and more rarely, emiction, is the process of disposing of urine from the urinary bladder through the urethra to the outside of the body. In healthy humans, the process of urination is under voluntary control; in infants and individuals with...

 and excreted through the urethra
Urethra
In anatomy, the urethra is a tube which connects the urinary bladder to the outside of the body. The urethra has an excretory function in both sexes to pass urine to the outside, and also a reproductive function in the male, as a passage for semen.The external urethral sphincter is a striated...

. Cellular metabolism generates numerous waste compounds, many rich in nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N and atomic number 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions, constituting 78% by volume of Earth's atmosphere.Many industrially important...

, that require elimination from the bloodstream. This waste is eventually expelled from the body in a process known as micturition, the primary method for excreting water-soluble chemicals from the body. These chemicals can be detected and analyzed by urinalysis
Urinalysis
A urinalysis is an array of tests performed on urine and one of the most common methods of medical diagnosis. A part of a urinalysis can be performed by using urine dipsticks, in which the test results can be read as color changes....

. Amniotic fluid
Amniotic fluid
Amniotic fluid or liquor amnii is the nourishing and protecting liquid contained by the amniotic sac of a pregnant woman. The amniotic sac grows and begins to fill, mainly with water, around two weeks after fertilization. After a further 10 weeks the liquid contains proteins, carbohydrates, lipids...

 is closely related to urine, and can be analyzed by amniocentesis
Amniocentesis
Amniocentesis , is a medical procedure used in prenatal diagnosis of chromosomal abnormalities and fetal infections , in which a small amount of amniotic fluid, which contains fetal tissues, is extracted from the amnion or amniotic sac surrounding a developing fetus, and the fetal DNA is examined...

.

Physiology



To eliminate soluble wastes, which are toxic, most animals have excretory system
Excretory system
The excretory system is a biological system that removes excess, unnecessary or dangerous materials from an organism. It is responsible for the elimination of oxygen waste products of metabolism as well as other nitrogeneous materials. Since the normal operation of most biological systems creates...

s. In humans soluble wastes are excreted by way of the urinary system
Urinary system
The urinary system is the organ system that produces, stores, and eliminates urine. In humans it includes two kidneys, two ureters, the bladder, the urethra, and the penis in males...

, which consists of the kidney
Kidney
The kidneys are paired organs, which have the production of urine as their primary function. Kidneys are seen in many types of animals, including vertebrates and some invertebrates. They are part of the urinary system, but have several secondary functions concerned with homeostatic functions. ...

s, ureter
Ureter
In human anatomy, the ureters are muscular ducts that propel urine from the kidneys to the urinary bladder. In the adult, the ureters are usually long....

s, urinary bladder
Urinary bladder
In anatomy, the urinary bladder is the organ that collects urine excreted by the kidneys prior to disposal by urination. A hollow muscular, and distensible organ, the bladder sits on the pelvic floor...

, and urethra
Urethra
In anatomy, the urethra is a tube which connects the urinary bladder to the outside of the body. The urethra has an excretory function in both sexes to pass urine to the outside, and also a reproductive function in the male, as a passage for semen.The external urethral sphincter is a striated...

. The kidneys extract the soluble wastes from the bloodstream, as well as excess water, sugars, and a variety of other compounds. The composition of urine is adjusted in the process of reabsorption whereby certain solutes, such as glucose
Glucose
Glucose , a monosaccharide also known as - grape sugar, blood sugar, or corn sugar, is a very important carbohydrate in biology. The living cell uses it as a source of energy and metabolic intermediate...

, are reabsorbed back into the blood stream via carrier molecules. The remaining fluid contains high concentrations of urea
Urea
Urea or carbamide is an organic compound with the chemical formula 2CO. The molecule has two amine residues joined by a carbonyl functional group....

 and other substances, including toxins. Urine flows through these structures: the kidney
Kidney
The kidneys are paired organs, which have the production of urine as their primary function. Kidneys are seen in many types of animals, including vertebrates and some invertebrates. They are part of the urinary system, but have several secondary functions concerned with homeostatic functions. ...

, ureter
Ureter
In human anatomy, the ureters are muscular ducts that propel urine from the kidneys to the urinary bladder. In the adult, the ureters are usually long....

, bladder
Urinary bladder
In anatomy, the urinary bladder is the organ that collects urine excreted by the kidneys prior to disposal by urination. A hollow muscular, and distensible organ, the bladder sits on the pelvic floor...

, and finally the urethra
Urethra
In anatomy, the urethra is a tube which connects the urinary bladder to the outside of the body. The urethra has an excretory function in both sexes to pass urine to the outside, and also a reproductive function in the male, as a passage for semen.The external urethral sphincter is a striated...

. Urine is produced by a process of filtration
Filtration
Filtration is a mechanical or physical operation which is used for the separation of solids from fluids by interposing a medium through which only the fluid can pass...

, reabsorption
Absorption (chemistry)
Absorption, in chemistry, is a physical or chemical phenomenon or a process in which atoms, molecules, or ions enter some bulk phase - gas, liquid or solid material. This is a different process from adsorption, since molecules undergoing absorption are taken up by the volume, not by the surface...

, and tubular secretion.

Composition


Urine is a transparent solution that can range from colorless to amber but is usually a pale yellow. Urine is an aqueous solution of approximately 95% water, with the remaining percentages being metabolic wastes such as urea
Urea
Urea or carbamide is an organic compound with the chemical formula 2CO. The molecule has two amine residues joined by a carbonyl functional group....

, dissolved salts, and organic compounds. Fluid and materials being filtered by the kidneys, destined to become urine, come from the blood or interstitial fluid
Interstitial fluid
Interstitial fluid is a solution that bathes and surrounds the cells of multicellular animals. It is the main component of the extracellular fluid, which also includes plasma and transcellular fluid...

.

Except in cases of kidney or urinary tract infection
Urinary tract infection
A urinary tract infection is a bacterial infection that affects any part of the urinary tract.The main causitive agent is:Escherichia coli. Although urine contains a variety of fluids, salts, and waste products, it usually does not have bacteria in it. When bacteria get into the bladder or kidney...

 (UTI), urine is virtually sterile
Sterilization (microbiology)
Sterilization refers to any process that effectively kills or eliminates transmissible agents from a surface, equipment, article of food or medication, or biological culture medium. Sterilization does not, however, remove prions...

 and nearly odorless. Subsequent to elimination from the body, urine can acquire strong odors due to bacterial action. Most noticeably, the asphyxiating ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula NH3. It is normally encountered as a gas with a characteristic pungent odor. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to foodstuffs and fertilizers...

 is produced by breakdown of urea. Some diseases alter the quantity and consistency of the urine, such as sugar
Sugar
Sugar is a class of edible crystalline substances, mainly sucrose, lactose, and fructose. Human taste buds interpret its flavor as sweet. Sugar as a basic food carbohydrate primarily comes from sugar cane and from sugar beet, but also appears in fruit, honey, sorghum, sugar maple , and in many...

 as a consequence of diabetes.

Hazards


Urea is toxic and can be irritating to skin and eyes. High concentrations in the blood can cause damage to organs of the body. However, after suitable processing (as is done, for example, on the International Space Station
International Space Station
The International Space Station is an internationally developed research facility currently being assembled in Low Earth Orbit. On-orbit construction of the station began in 1998 and is scheduled to be completed by 2011, with operations continuing until at least 2015...

), it is possible to extract potable water for drinking.

Characteristics


The typical color of urine is caused by the pigment urochrome as well as the degradation products of bilirubin
Bilirubin
Bilirubin is the yellow breakdown product of normal heme catabolism. Heme is found in hemoglobin, a principal component of red blood cells. Bilirubin is excreted in bile, and its levels are elevated in certain diseases...

 and urobilin
Urobilin
Urobilin is a yellow linear tetrapyrrole, resulting from the breakdown of heme, a cyclic tetrapyrrole...

. It can range from clear to a dark amber, depending mostly upon the level of hydration of the body, among other factors.

Chemical analysis




Urine contains a range of substances that vary with what is introduced into the body. Aside from water, urine contains an assortment of inorganic salts and organic compounds, including proteins, hormones, and a wide range of metabolites.

Unusual color

  • Colorless- indicates over-hydration, which is usually considered much healthier than dehydration. In the context of a drug test, it could indicate a potential attempt to avoid detection of illicit drugs in the bloodstream through over-hydration.
  • Yellowing/light orange may be caused by removal of excess B vitamins from the bloodstream.
  • Certain medications such as rifampin and pyridium can cause orange urine.
  • Bloody urine is termed hematuria
    Hematuria
    In medicine, hematuria, or haematuria, is the presence of red blood cells in the urine. It may be idiopathic and/or benign, or it can be a sign that there is a kidney stone or a tumor in the urinary tract , ranging from trivial to lethal...

    , potentially a sign of a bladder infection.
  • Consumption of beets can cause urine to have a pinkish tint; the condition is harmless and temporary.
  • Dark orange to brown urine can be a symptom of jaundice
    Jaundice
    Jaundice, also known as icterus , is a yellowish discoloration of the skin, the conjunctival membranes over the sclerae , and other mucous membranes caused by hyperbilirubinemia...

    , rhabdomyolysis
    Rhabdomyolysis
    Rhabdomyolysis is the rapid breakdown of skeletal muscle due to injury to muscle tissue. The muscle damage may be caused by physical , chemical, or biological factors...

    , or Gilbert's syndrome
    Gilbert's syndrome
    Gilbert's syndrome, pronounced 'zheel-BAYR', often shortened to GS, also called Gilbert-Meulengrachts syndrome, is the most common hereditary cause of increased bilirubin and is found in up to 5% of the population...

    .
  • Black or dark-colored urine is referred to as melanuria and may be caused by a melanoma
    Melanoma
    Melanoma is a malignant tumor of melanocytes which are found predominantly in skin but also in the bowel and the eye . It is one of the less common types of skin cancer but causes the majority of skin cancer related deaths. Melanocytes are normally present in skin, being responsible for the...

    .
  • Reddish or brown urine may be caused by porphyria
    Porphyria
    Porphyrias are a group of inherited or acquired disorders of certain enzymes in the heme biosynthetic pathway . They are broadly classified as acute porphyrias and cutaneous porphyrias, based on the site of the overproduction and accumulation of the porphyrins...

    . Again, the consumption of beets can cause the urine to have a harmless, temporary pink or reddish tint.
  • Greenish color is usually a consequence of consuming asparagus.
  • Fluorescent yellow / greenish urine may be caused by dietary supplemental vitamins, especially the B vitamins.
  • Dark yellow urine is usually indicative of dehydration.

Odor


The smell of urine can be affected by the consumption of food. Eating asparagus is known to produce a strong odour in human urine. This is due to the body's breakdown of asparagusic acid
Asparagusic acid
Asparagusic acid, S22CHCO2H is an organosulfur carboxylic acid present in the vegetable asparagus and may be the metabolic precursor to other odorous thiol compounds. Biosynthetic studies revealed that asparagusic acid is derived from isobutyric acid. This colorless...

. Other foods that contribute to odor include curry
Curry
Curry is a generic description used throughout European and American culture to describe a general variety of spiced dishes, best known in Asian cuisines, especially South Asian cuisine...

, alcohol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug, best known as the type of alcohol found in alcoholic beverages and in modern thermometers. Ethanol is one of the oldest recreational drugs...

, coffee
Coffee
Coffee is a brewed beverage prepared from roasted seeds, commonly called coffee beans, of the coffee plant. They are seeds of "coffee cherries" that grow on trees in over 70 countries. It has been said that green coffee is the second most traded commodity in the world behind crude oil. Due to its...

, turkey and onion
Onion
Onion is a term used for many plants in the genus Allium. They are known by the common name "onion" but, used without qualifiers, it usually refers to Allium cepa. Allium cepa is also known as the "garden onion" or "bulb" onion...

.

Turbidity


Turbid
Turbidity
Turbidity is the cloudiness or haziness of a fluid caused by individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality....

 urine may be a symptom of a bacterial infection, but can also be due to crystallization of salts such as calcium phosphate
Calcium phosphate
Calcium phosphate is the name given to a family of minerals containing calcium ions together with orthophosphates , metaphosphates or pyrophosphates and occasionally hydrogen or hydroxide ions.It is the principal form of calcium found in bovine milk...

.

pH


The pH
PH
pH is a measure of the acidity or basicity of a solution. It is defined as the cologarithm of the activity of dissolved hydrogen ions . Hydrogen ion activity coefficients cannot be measured experimentally, so they are based on theoretical calculations...

 of urine is close to neutral (7) but can normally vary between 6.5 and 7.4 In persons with hyperuricosuria
Hyperuricosuria
Hyperuricosuria is a medical term referring to the presence of excessive amounts of uric acid in the urine. Notable direct causes of hyperuricosuria are dissolution of uric acid crystals in the kidneys or urinary bladder, and hyperuricemia...

, acidic urine can contribute to the formation of stones
Calculus (medicine)
A calculus is a stone that forms in an organ or duct of the body. Formation of calculi is known as lithiasis...

 of uric acid
Uric acid
Uric acid is an organic compound of carbon, nitrogen, oxygen and hydrogen with the formula C5H4N4O3.-Biology:...

 in the kidneys, ureters, or bladder. Urine pH can be monitored by a physician or at home.

Volume


The amount of urine produced depends on numerous factors including state of hydration, activities, environmental factors, size, and health. In adult humans the average production is about 1 - 2 L per day. Producing too much or too little urine needs medical attention: Polyuria
Polyuria
In medicine, polyuria is a condition characterized by the passage of large volumes of urine .Polyuria often appears in conjunction with polydipsia , though it is possible to have one without the other, and the latter may be a cause or an effect...

 is a condition of excessive production of urine (> 2.5 L/day), in contrast to oliguria
Oliguria
Oliguria is the decreased production of urine. The decreased production of urine may be a sign of dehydration, renal failure, hypovolemic shock or urinary obstruction/urinary retention....

 where < 400 mL are produced per day, or anuria
Anuria
Anuria means nonpassage of urine. But, is practically defined as passage of less than 50 milliliters of urine in a day. Anuria is inability to urinate due to failure in the function of kidneys. It may also occur because of some severe obstruction like kidney stones or tumours...

 with a production of < 100 mL per day.

Density or specific gravity


Normal urine density or specific gravity values vary between 1.003–1.035 (g·cm−3) , and any deviations may or may not be associated with urinary disorders.

Examination


Many physicians in history have resorted to the inspection and examination of the urine of their patients. Hermogenes
Hermogenes
Hermogenes is a Greek name.Notable people bearing this name include:*Hermogenes , a follower of Socrates, who lived in the late 5th century BCE-early 4th century BCE and was mentioned by Plato and Xenophon...

 wrote about the color and other attributes of urine as indicators of certain diseases. Abdul Malik Ibn Habib of Andalusia
Andalusia
Andalusia Andalusia Andalusia ' onMouseout='HidePop("64842")' href="http://www.absoluteastronomy.com/topics/Umayyad">Umayyad
Umayyad
The Umayyad Caliphate was the second of the four Islamic caliphates established after the death of Muhammad. It was ruled by the Umayyad dynasty, whose name derives from Umayya ibn Abd Shams, the great-grandfather of the first Umayyad caliph. Although the Umayyad family originally came from the...

 empire. Diabetes mellitus
Diabetes mellitus
Diabetes mellitus —often referred to simply as diabetes—is a condition in which the body either does not produce enough, or does not properly respond to, insulin, a hormone produced in the pancreas. Insulin enables cells to absorb glucose in order to turn it into energy...

 got its name because the urine is plentiful and sweet. A urinalysis
Urinalysis
A urinalysis is an array of tests performed on urine and one of the most common methods of medical diagnosis. A part of a urinalysis can be performed by using urine dipsticks, in which the test results can be read as color changes....

 is a medical examination of the urine and part of routine examinations. A culture of the urine is performed when a urinary tract infection
Urinary tract infection
A urinary tract infection is a bacterial infection that affects any part of the urinary tract.The main causitive agent is:Escherichia coli. Although urine contains a variety of fluids, salts, and waste products, it usually does not have bacteria in it. When bacteria get into the bladder or kidney...

 is suspected. A microscopic examination of the urine may be helpful to identify organic or inorganic substrates and help in the diagnosis.

The color and volume of urine can be reliable indicators of hydration
Rehydration
Rehydration is the replenishment of water, or water and electrolytes, lost through dehydration.In humans, methods of rehydration include oral rehydration therapy or intravenous therapy. As oral rehydration is less painful, less invasive, less expensive, and easier to provide, it is the treatment...

 level. Clear and copious urine is generally a sign of adequate hydration, dark urine is a sign of dehydration
Dehydration
Dehydration is defined as excessive loss of body water. It is literally the removal of water from an object. In physiological terms, it entails a relative deficiency of water molecules in relation to other dissolved solutes...

. The exception is when alcohol
Alcohol
In chemistry, an alcohol is any organic compound in which a hydroxyl group is bound to a carbon atom of an alkyl or substituted alkyl group. An important group of acohols is formed by the simple acyclic alcohols, the general formula for which is CnH2n+1OH...

, caffeine
Caffeine
Caffeine is a bitter, white crystalline xanthine alkaloid that is a psychoactive stimulant drug. Caffeine was discovered by a German chemist, Friedrich Ferdinand Runge, in 1819. He coined the term kaffein, a chemical compound in coffee, which in English became caffeine...

, or other diuretics are consumed, in which case urine can be clear and copious and the person still be dehydrated.

Application


Aztec physicians used urine to clean external wounds to prevent infection, and administered it as a drink to relieve stomach and intestinal problems. Purported advocates of the urine 'cure' include Jim Morrison
Jim Morrison
James Douglas "Jim" Morrison was an American singer, songwriter, poet, writer and filmmaker. He was best known as the lead singer and lyricist of The Doors and is widely considered to be one of the most charismatic frontmen in rock music history. He was also the author of several books of poetry ...

 and Steve McQueen
Steve McQueen
Terrence Steven "Steve" McQueen was an American movie actor nicknamed, "The King of Cool." His "anti-hero" persona, which he developed at the height of the Vietnam counterculture, made him one of the top box-office draws of the 1960s and 1970s. McQueen received an Academy Award nomination for his...

 . Its alleged medicinal properties have also been utilized in China as a part of holistic medicine, and in India, especially as part of the traditional Indian medicine, Ayurveda
Ayurveda
Ayurveda is a system of traditional medicine native to India and practiced in other parts of the world as a form of alternative medicine. In Sanskrit, the word Ayurveda consists of the words , meaning 'life', and , meaning 'related to knowledge' or 'science'...

, under the name Amaroli . The use of urine therapy
Urine therapy
In alternative medicine, the term urine therapy refers to various applications of human urine for medicinal or cosmetic purposes, including drinking of one's own urine and massaging one's skin with one's own urine. A practitioner of urine therapy is sometimes called a uropath...

 as a medical treatment or daily health regimen is typically shunned in the West .

Resource


Urine contains proteins and other substances that are useful for medical therapy and are ingredients in many prescription drugs (e.g., Ureacin, Urecholine, Urowave). Urine from postmenopausal
Menopause
Menopause is the time in a woman’s life when menstruation ends. It is part of a biological process that begins, for most women, in their mid-fifties. During this time, the ovaries gradually produce lower levels of natural sex hormones—estrogen and progesterone...

 women is rich in gonadotropin
Gonadotropin
Gonadotropins are protein hormones secreted by gonadotrope cells of the pituitary gland of vertebrates.Gonadotropin is sometimes abbreviated Gn. The British spelling is gonadotrophin.-Types:...

s that can yield follicle stimulating hormone and luteinizing hormone
Luteinizing hormone
Luteinizing hormone is a hormone produced by the anterior pituitary gland.* In the female, an acute rise of LH – the LH surge – triggers ovulation and corpus luteum development....

 for fertility therapy. The first such commercial product was Pergonal. Urine from pregnant women contains enough human chorionic gonadotropin
Human chorionic gonadotropin
Human chorionic gonadotropin or Human chorionic gonadotrophin is a glycoprotein hormone produced in pregnancy that is made by the developing embryo soon after conception and later by the syncytiotrophoblast...

s for commercial extraction and purification to produce hCG medication. Pregnant mare urine is the source of estrogen
Estrogen
Estrogens are a group of steroid compounds, named for their importance in the estrous cycle, and functioning as the primary female sex hormone, their name comes from estrus/oistros + gen/gonos = to generate.Estrogens are used as part of some oral contraceptives, in estrogen replacement...

s, namely Premarin
Premarin
Premarin is the commercial name for compound drug consisting primarily of conjugated estrogens. Isolated from mare's urine , it is manufactured by Wyeth Pharmaceuticals and has been marketed since 1942...

.

In recent times, the Port-A-John
Portable toilet
A portable toilet is a modern, portable, self-contained outhouse manufactured of molded plastic in a variety of colors and is often used as a temporary toilet for construction sites and large gatherings and events...

 corporation of Utica, Michigan
Utica, Michigan
Utica is a city in Macomb County in the U.S. state of Michigan. The population was 4,577 at the 2000 census.- History :The city now known as Utica was platted by Joseph Stead in 1829, who preferred to call it "Harlow." Others referred to the city as "Hog Hollow" or "McDougalville," until a few...

, USA has developed a filter to collect medically significant protein
Protein
Proteins are organic compounds made of amino acids arranged in a linear chain and folded into a globular form. The amino acids in a polymer chain are joined together by the peptide bonds between the carboxyl and amino groups of adjacent amino acid residues...

s from users of their chemical toilets.

Ancient uses

  • The ancient Romans
    Ancient Rome
    Ancient Rome was a civilization that grew out of a small agricultural community founded on the Italian Peninsula as early as the 10th century BC. Located along the Mediterranean Sea, it became one of the largest empires in the ancient world....

     used urine as a bleach
    Bleach
    A bleach is a chemical that removes colors or whitens, often via oxidation. Common chemical bleaches include household "chlorine bleach", a solution of approximately 3–6% sodium hypochlorite , and "oxygen bleach", which contains hydrogen peroxide or a peroxide-releasing compound such as sodium...

    ing agent for cleaning clothes and teeth.
  • In Scotland
    Scotland
    Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

    , it was used to wash wool to prevent shrinking.

Munitions



Urine has been used in the manufacture of gunpowder
Gunpowder
Gunpowder, also called black powder, is a mixture of sulfur, charcoal, and potassium nitrate. It burns rapidly, producing volumes of hot solids and gases which can be used as a propellant in firearms and as a pyrotechnic composition in fireworks. The term gunpowder also refers broadly to any...

. Urine, a nitrogen source, was used to moisten straw or other organic material, which was kept moist and allowed to rot for several months to over a year. The resulting salts were washed from the heap with water, which was evaporated to allow collection of crude saltpeter crystals, that were usually refined before being used in making gunpowder.

Textiles


Urine has often been used as a mordant
Mordant
A mordant is a substance used to set dyes on fabrics or tissue sections by forming a coordination complex with the dye which then attaches to the fabric or tissue. It may be used for dyeing fabrics, or for intensifying stains in cell or tissue preparations. A mordant is always a polyvalent metal ion...

 to help prepare textiles, especially wool, for dyeing. In Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

, the process of "walking" (stretching) the tweed
Tweed (cloth)
Tweed is a rough, coarse, unfinished woollen fabric, of a soft, open, flexible texture resembling cheviot or homespun, but more closely woven. It is made in either plain or twill weave and may have a check or herringbone pattern...

 is preceded by soaking in urine.

Urine was used for dyes such as indigo
Indigo
Indigo is the color on the electromagnetic spectrum between about 420 and 450 nm in wavelength, placing it between blue and violet. Although traditionally considered one of seven divisions of the optical spectrum, modern color scientists do not usually recognize indigo as a separate division and...

 where the urea in the urine reacted with the insoluble dye to form a soluble solution.

Agriculture


Urine contains large quantities of nitrogen (mostly as urea
Urea
Urea or carbamide is an organic compound with the chemical formula 2CO. The molecule has two amine residues joined by a carbonyl functional group....

), as well as significant quantities of dissolved phosphates and potassium, the main macronutrients required by plants. Diluted at least 8:1 with water it can be applied directly to soil as a fertilizer. Undiluted, it can chemically burn the roots of some plants, but it can be safely used as a source of complementary nitrogen in carbon rich compost
Compost
Compost is a combination of food material and other organic material that is being decomposed through aerobic decomposition into a rich black soil. The process of composting is simple and practiced by individuals in their homes, farmers on their land, and industrially by cities.Compost soil is...

.
Urine typically contains 70% of the nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N and atomic number 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions, constituting 78% by volume of Earth's atmosphere.Many industrially important...

 and more than half the phosphorus
Phosphorus
Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus is commonly found in inorganic phosphate rocks. Elemental phosphorus exists in two major forms - white phosphorus and red phosphorus...

 and potassium
Potassium
Potassium is the chemical element with the symbol K , atomic number 19, and atomic mass 39.0983. Potassium was first isolated from potash...

 found in urban waste water flows, while making up less than 1% of the overall volume. Thus source separation and on-site treatment has been studied in Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe...

 as a way to partially close the cycle of agricultural nutrient flows, to reduce the cost and energy intensivity of sewage treatment, and the ecological consequences such as eutrophication
Eutrophication
Eutrophication is an increase in the concentration of chemical nutrients in an ecosystem to an extent that increases in the primary productivity of the ecosystem...

, resulting from an influx of nutrient rich effluent into aquatic or marine ecosystems. The fertilization effect of urine has been found to be comparable to that of commercial fertilizers with an equivalent NPK rating
NPK rating
NPK rating is the acronym for the ratio of the chemicals nitrogen, phosphorus, and potassium that are commonly used in fertilizers....

.
However, depending on the diet of the producer, urine may also have undesirably high concentrations of various inorganic salt
Salt
A salt, in chemistry, is an ionic compound, and can result from the neutralization reaction of acids and bases. Salts are ionic compounds composed of cations and anions so that the product is electrically neutral...

s such as sodium chloride
Sodium chloride
Sodium chloride, also known as salt, common salt, table salt, or halite, is an ionic compound with the formula NaCl. Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multicellular organisms...

, which are also excreted by the renal system. Concentrations of heavy metals such as lead
Lead
Lead is a main-group element with symbol Pb and atomic number 82. Lead is a soft, malleable poor metal, also considered to be one of the heavy metals. Lead has a bluish-white color when freshly cut, but tarnishes to a dull grayish color when exposed to air...

, mercury
Mercury (element)
Mercury , also called quicksilver or hydrargyrum , is a chemical element with the symbol Hg and atomic number 80...

, and cadmium
Cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48. The soft, bluish-white transition metal is chemically similar to the two other metals in group 12, zinc and mercury. Similar to zinc it prefers oxidation state +2 in most of its compounds and similar to mercury it shows a low...

, commonly found in solid human waste, are much lower in urine (though not low enough to qualify for use in organic agriculture under current EU rules).
Some have expressed concern as to the health consequences of the hormones and pharmaceuticals found in the human waste stream being recycled through the agricultural system. Proponents of urine as an agricultural fertilizer usually claim the risks to be negligible or acceptable, and point out that sewage causes more environmental problems when it is treated and disposed of compared with when it is used as a resource. Critics counter that more research is needed into how the resource is to be collected, processed and handled.

It is unclear whether source separation and on site treatment of urine can be made cost effective, and to what degree the required behavioral changes would be regarded as socially acceptable, as the largely successful trials performed in Sweden may not readily generalize to other industrialized societies. In developing countries, the application of pure urine to crops is rare, but the use of whole raw sewage (termed night soil
Night soil
Night soil is a euphemism for human feces. "Night soil" is produced as a result of a waste management system in areas without community infrastructure such as a sewage treatment facility, or individual septic disposal...

 in China) has been common throughout history.

Survival uses



Numerous survival instructors and guides, including the US Army Field Manual, advise against drinking urine for survival. These guides explain that drinking urine tends to worsen, rather than relieve dehydration due to the salts in it, and that urine should not be consumed in a survival situation, even when there is no other fluid available.

During World War I
World War I
World War I , also known as the First World War, the Great War, and the War to End All Wars, was a global military conflict which involved most of the world's great powers, assembled in two opposing alliances: the Triple Entente and the Triple Alliance...

, the Germans
Germans
The German people are an ethnic group, in the sense of sharing a common German culture, descent, and speaking the German language as a mother tongue. Within Germany, Germans are defined by citizenship , distinguished from people of German ancestry...

 experimented with numerous poisonous gases for use during war. After the first German chlorine
Chlorine
Chlorine Chlorine Chlorine ( , from the Greek word 'χλωρóς' (khlôros, meaning 'pale green'), is the chemical element with atomic number 17 and symbol Cl. It is a halogen, found in the periodic table in group 17 (formerly VII, VIIa, or VIIb). As the chloride ion, which is part of common salt and...

 gas attacks, Allied troops were supplied with masks of cotton pads that had been soaked in urine. It was believed that the ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula NH3. It is normally encountered as a gas with a characteristic pungent odor. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to foodstuffs and fertilizers...

 in the pad neutralized the chlorine. These pads were held over the face until the soldiers could escape from the poisonous fumes, although it is now known that chlorine gas reacts with urine to produce toxic fumes
Chloramine
Chloramine is a chemical compound with the formula NH2Cl. It is usually used as a dilute solution where it is used as a disinfectant. The term chloramine also refers to a family of organic compounds with the formulas R2NCl and RNCl2...

 (see chlorine
Chlorine
Chlorine Chlorine Chlorine ( , from the Greek word 'χλωρóς' (khlôros, meaning 'pale green'), is the chemical element with atomic number 17 and symbol Cl. It is a halogen, found in the periodic table in group 17 (formerly VII, VIIa, or VIIb). As the chloride ion, which is part of common salt and...

 and Use of poison gas in World War I).

Urine has also been historically used as an antiseptic. In times of war, when other antiseptics were unavailable, urine, the darker the better, was utilized on open wounds as an antibacterial.

Urban myth states that urine works well against jellyfish
Jellyfish
Jellyfish are free-swimming members of the phylum Cnidaria. Jellyfish have several different morphologies that represent several different cnidarian classes including the Scyphozoa , Staurozoa , Cubozoa , and Hydrozoa Jellyfish (also known as jellies or sea jellies) are free-swimming members of...

 stings, and this scenario was demonstrated on an early episode of the CBS-TV show Survivor
Survivor (U.S. TV series)
Survivor is an American version of the Survivor reality television game show, itself derived from the Swedish television series Expedition Robinson originally created in 1997 by Charlie Parsons, and first broadcast in May 2000. Mark Burnett produces the American series. Its host is the former game...

. At best, it is ineffective and in some cases this treatment may make the injury worse.

History


The yellow color of urine was previously thought to come from gold. Alchemists
Alchemy
Alchemy is both a philosophy and a practice with an aim of achieving ultimate wisdom as well as immortality, involving the improvement of the alchemist as well as the making of several substances described as possessing unusual properties...

 spent much time trying to extract gold from urine, and this effort led to discoveries such as white phosphorus, which was discovered by the German alchemist Hennig Brand
Hennig Brand
Hennig Brand was a merchant and alchemist in Hamburg, Germany who discovered phosphorus around 1669.-Early life:The circumstances of Brand's birth are unknown. Some sources describe his origins as humble and indicate that he had been an apprentice glass-maker as a young man...

 in 1669 when he was distilling fermented
Fermentation (biochemistry)
Fermentation is the process of deriving energy from the oxidation of organic compounds, such as carbohydrates, using an endogenous electron acceptor, which is usually an organic compound. This is in contrast to cellular respiration, where electrons are donated to an exogenous electron acceptor,...

 urine. In 1773 the French chemist Hilaire Rouelle
Hilaire Rouelle
Hilaire Marin Rouelle was a French chemist. In 1773, he discovered urea. He is known as "le cadet" to distinguish him from his older brother, Guillaume-François Rouelle, who was also a chemist....

 discovered the organic compound urea
Urea
Urea or carbamide is an organic compound with the chemical formula 2CO. The molecule has two amine residues joined by a carbonyl functional group....

 by boiling urine dry.

The word "urine" was first used in the 14th century. Before that, the concept was described by the now vulgar word "piss". Onomatopoetic
Onomatopoeia
An onomatopoeia or onomatopœia, from the Greek ὀνοματοποιία , is a word that imitates or suggests the source of the sound that it describes. Onomatopoeia refers to the property of such words. Common occurrences of onomatopoeias include animal noises, such as "oink" or "meow" or...

 in origins, "piss" was the primary means of describing urination, as "urinate" was at first used mostly in medical contexts. Likely, "piss" became vulgar through its use by lower class characters such as the reeve and the Wife of Bath in Geoffrey Chaucer's
Geoffrey Chaucer
Geoffrey Chaucer was an English author, poet, philosopher, bureaucrat, courtier and diplomat. Although he wrote many works, he is best remembered for his unfinished frame narrative The Canterbury Tales...

 14th century work The Canterbury Tales
The Canterbury Tales
The Canterbury Tales is a collection of stories written by Geoffrey Chaucer in the 14th century . The tales are contained inside a frame tale and told by a collection of pilgrims on a pilgrimage from Southwark to visit the shrine of Saint Thomas Becket at Canterbury Cathedral...

. "Piss" and its association with vulgarity has led to its current classification as obscene, as well as its use in such colloquial expressions as "to piss off", "piss poor", and others.

See also

  • Ecological sanitation
    Ecological sanitation
    Ecological sanitation, also known as ecosan or eco-san, is a sanitation process that uses human excreta and household wastewater as resources to be recovered, treated , and reused, instead of as waste...

  • Urolagnia
    Urolagnia
    Urolagnia is a paraphilia in which sexual excitement is associated with the sight or thought of urine or urination. The term has origins in the Greek Language ....

    , an attraction to urine
  • Urination
    Urination
    Urination, also known as micturition, voiding, peeing, and more rarely, emiction, is the process of disposing of urine from the urinary bladder through the urethra to the outside of the body. In healthy humans, the process of urination is under voluntary control; in infants and individuals with...

  • Urine therapy
    Urine therapy
    In alternative medicine, the term urine therapy refers to various applications of human urine for medicinal or cosmetic purposes, including drinking of one's own urine and massaging one's skin with one's own urine. A practitioner of urine therapy is sometimes called a uropath...

  • Drinking urine
  • Bed-Wetting

External links