A urine test is any

medical test A medical test is a medical procedure performed to detect, diagnose, or monitor diseases, disease processes, susceptibility, or to determine a course of treatment. Medical tests such as, physical and visual exams, diagnostic imaging, geneti ...

performed on a

urine Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra. Cellular ...

specimen. The analysis of urine is a valuable diagnostic tool because its composition reflects the functioning of many body systems, particularly the

kidney The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; bloo ...

s and

urinary system The urinary system, also known as the urinary tract or renal system, consists of the kidneys, ureters, bladder, and the urethra. The purpose of the urinary system is to eliminate waste from the body, regulate blood volume and blood pressure, ...

, and specimens are easy to obtain. Common urine tests include the routine

urinalysis Urinalysis, a portmanteau of the words ''urine'' and ''analysis'', is a panel of medical tests that includes physical (macroscopic) examination of the urine, chemical evaluation using urine test strips, and microscopic examination. Macroscopic ...

, which examines the physical, chemical, and microscopic properties of the urine; urine drug screening; and urine pregnancy testing.

Background

The value of urine for diagnostic purposes has been recognized since ancient times. Urine examination was practiced in Sumer and

Babylonia Babylonia (; Akkadian: , ''māt Akkadī'') was an ancient Akkadian-speaking state and cultural area based in the city of Babylon in central-southern Mesopotamia (present-day Iraq and parts of Syria). It emerged as an Amorite-ruled state ...

as early as 4000 BC, and is described in ancient

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

and

Sanskrit Sanskrit (; attributively , ; nominalization, nominally , , ) is a classical language belonging to the Indo-Aryan languages, Indo-Aryan branch of the Indo-European languages. It arose in South Asia after its predecessor languages had Trans-cul ...

texts. Contemporary urine testing uses a range of methods to investigate the physical and biochemical properties of the urine. For instance, the results of the routine

can provide information about the functioning of the

kidneys The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; bloo ...

and

; suggest the presence of a

urinary tract infection A urinary tract infection (UTI) is an infection that affects part of the urinary tract. When it affects the lower urinary tract it is known as a bladder infection (cystitis) and when it affects the upper urinary tract it is known as a kidne ...

(UTI); and screen for possible

diabetes Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level (hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ...

liver disease Liver disease, or hepatic disease, is any of many diseases of the liver. If long-lasting it is termed chronic liver disease. Although the diseases differ in detail, liver diseases often have features in common. Signs and symptoms Some of the s ...

, among other conditions. A urine culture can be performed to identify the bacterial species involved in a UTI. Simple

point-of-care test Point-of-care testing (POCT or bedside testing) is defined as medical diagnostic testing at or near the point of care—that is, at the time and place of patient care. This contrasts with the historical pattern in which testing was wholly or most ...

s can detect

pregnancy Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occurs by sexual intercourse, but ...

by identifying the presence of beta-hCG in the urine and indicate the use of recreational drugs by detecting excreted drugs or their metabolites. Analysis of abnormal cells in urine ( urine cytology) can help to diagnose some

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal bl ...

s, and testing for

organic acids An organic acid is an organic compound with acidic properties. The most common organic acids are the carboxylic acids, whose acidity is associated with their carboxyl group –COOH. Sulfonic acids, containing the group –SO2OH, are ...

or amino acids in urine can be used to screen for some

genetic disorder A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosomal abnormality. Although polygenic disorde ...

Specimen collection

Trace metal-free 24 hour urine container

The techniques used to collect urine specimens vary based on the desired test. A random urine, meaning a specimen that is collected at any time, can be used for many tests. However, a sample collected during the first urination of the morning (first morning specimen) is preferred for tests like urinalysis and pregnancy screening because it is typically more concentrated, making the test more sensitive. Because the concentration of many substances in the urine varies throughout the day, some tests require timed urine collections, in which the patient collects all of their urine into a container for a given period of time (commonly 24 hours). A small amount of the specimen is then removed for testing. Timed collections are commonly used to measure

creatinine Creatinine (; ) is a breakdown product of creatine phosphate from muscle and protein metabolism. It is released at a constant rate by the body (depending on muscle mass). Biological relevance Serum creatinine (a blood measurement) is an import ...

urea Urea, also known as carbamide, is an organic compound with chemical formula . This amide has two amino groups (–) joined by a carbonyl functional group (–C(=O)–). It is thus the simplest amide of carbamic acid. Urea serves an important ...

, urine protein,

hormones A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are required fo ...

and

electrolytes An electrolyte is a medium containing ions that is electrically conducting through the movement of those ions, but not conducting electrons. This includes most soluble salts, acids, and bases dissolved in a polar solvent, such as water. Upon d ...

. Research has shown many women are unsure of how to take a midstream sample or why it is needed. If urine is needed for

microbiological culture A microbiological culture, or microbial culture, is a method of multiplying microbial organisms by letting them reproduce in predetermined culture medium under controlled laboratory conditions. Microbial cultures are foundational and basic diag ...

, it is important that the sample is not contaminated. In this case, the proper collection procedure involves cleaning the genital area, beginning to urinate into the toilet, and then filling the specimen container before completing the urination into the toilet. This is called a "midstream clean catch" collection. If the subject is not able to urinate voluntarily, samples can be obtained using a

urinary catheter In urinary catheterization a latex, polyurethane, or silicone tube known as a urinary catheter is inserted into the bladder through the urethra to allow urine to drain from the bladder for collection. It may also be used to inject liquids used ...

or by inserting a needle through the abdomen and into the bladder (

suprapubic aspiration Suprapubic aspiration is a procedure to take a urine sample. It involves putting a needle through the skin just above the pubic bone into the bladder. It is typically used as a method to collect urine in child less than 2 years of age who is not ye ...

). In infants and young children, urine can be collected into a bag attached to the genital region, but this is associated with a high risk of contamination.

Types

Some examples of urine tests include:

Chemistry

Urinalysis Urinalysis, a portmanteau of the words ''urine'' and ''analysis'', is a panel of medical tests that includes physical (macroscopic) examination of the urine, chemical evaluation using urine test strips, and microscopic examination. Macroscopic ...

— assessment of the visual properties of the urine, chemical evaluation using urine test strips, and microscopic examination *

Urine creatinine Creatinine (; ) is a breakdown product of creatine phosphate from muscle and protein metabolism. It is released at a constant rate by the body (depending on muscle mass). Biological relevance Serum creatinine (a blood measurement) is an import ...

creatinine clearance Assessment of kidney function occurs in different ways, using the presence of symptoms and signs, as well as measurements using urine tests, blood tests, and medical imaging. Functions of a healthy kidney include maintaining a person's fluid ...

— used to assess kidney function *

Albumin/creatinine ratio Microalbuminuria is a term to describe a moderate increase in the level of urine albumin. It occurs when the kidney leaks small amounts of albumin into the urine, in other words, when an abnormally high permeability for albumin in the glomerulus ...

— used to diagnose

microalbuminuria Microalbuminuria is a term to describe a moderate increase in the level of urine albumin. It occurs when the kidney leaks small amounts of albumin into the urine, in other words, when an abnormally high permeability for albumin in the glomerulus o ...

* Urine osmolality — measure of the

solute In chemistry, a solution is a special type of homogeneous mixture composed of two or more substances. In such a mixture, a solute is a substance dissolved in another substance, known as a solvent. If the attractive forces between the solve ...

concentration of urine *

Urine specific gravity Specific gravity, in the context of clinical pathology, is a urinalysis parameter commonly used in the evaluation of kidney function and can aid in the diagnosis of various renal diseases. Background One of the main roles of the kidneys in ...

― another measure of urine concentration *

Urine electrolyte levels Urine electrolyte levels can be measured in a medical laboratory for diagnostic purposes. The urine concentrations of sodium, chloride and potassium may be used to investigate conditions such as abnormal blood electrolyte levels, acute kidney inju ...

— measurement of

such as

sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable ...

and

potassium Potassium is the chemical element with the symbol K (from Neo-Latin '' kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmosp ...

in urine *

Urine anion gap The urine anion gap is calculated using measured ions found in the urine. It is used to aid in the differential diagnosis of metabolic acidosis. The term "anion gap" without qualification usually implies serum anion gap. The "urine anion gap" is a ...

— used to distinguish between some causes of

metabolic acidosis Metabolic acidosis is a serious electrolyte disorder characterized by an imbalance in the body's acid-base balance. Metabolic acidosis has three main root causes: increased acid production, loss of bicarbonate, and a reduced ability of the kidne ...

Hormones

* Urine pregnancy test ― detects

human chorionic gonadotropin Human chorionic gonadotropin (hCG) is a hormone for the maternal recognition of pregnancy produced by trophoblast cells that are surrounding a growing embryo (syncytiotrophoblast initially), which eventually forms the placenta after implantati ...

in urine * Urine cortisol ― used to investigate disorders of the

adrenal gland The adrenal glands (also known as suprarenal glands) are endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. They are found above the kidneys. Each gland has an outer cortex w ...

s * Urine metanephrines ― used to help diagnose some rare

tumour A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

Microbiology

* Urine culture —

of urine samples, used to identify bacteria causing

Miscellaneous

* Urine drug screen — screen for usage of

recreational drug Recreational drug use indicates the use of one or more psychoactive drugs to induce an altered state of consciousness either for pleasure or for some other casual purpose or pastime by modifying the perceptions and emotions of the user. When a ...

s * Urine cytology —

cytopathological Cytopathology (from Greek , ''kytos'', "a hollow"; , ''pathos'', "fate, harm"; and , ''-logia'') is a branch of pathology that studies and diagnoses diseases on the cellular level. The discipline was founded by George Nicolas Papanicolaou in 19 ...

examination of cells in the urine, used to screen for cancer *

Urine protein electrophoresis Protein electrophoresis is a method for analysing the proteins in a fluid or an extract. The electrophoresis may be performed with a small volume of sample in a number of alternative ways with or without a supporting medium: SDS polyacrylamide gel ...

— classification and measurement of different

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...

s in the urine; used to help diagnose

monoclonal gammopathies Monoclonal gammopathy, also known as paraproteinemia, is the presence of excessive amounts of myeloma protein or monoclonal gamma globulin in the blood. It is usually due to an underlying immunoproliferative disorder or hematologic neoplasms, e ...

* Urine organic acids,

urine amino acids Aminoaciduria occurs when the urine contains abnormally high amounts of amino acids. In the healthy kidney, the glomeruli filter all amino acids out of the blood, and the renal tubules then reabsorb over 95% of the filtered amino acids back into t ...

— used to test for some

inborn errors of metabolism Inborn errors of metabolism form a large class of genetic diseases involving congenital disorders of enzyme activities. The majority are due to defects of single genes that code for enzymes that facilitate conversion of various substances (substra ...

References

Works cited

* * * * * * {{Urine tests Urine tests