Polyuria () is excessive or an abnormally large production or passage of

urine Urine is a liquid by-product of metabolism in humans and many other animals. In placental mammals, urine flows from the Kidney (vertebrates), kidneys through the ureters to the urinary bladder and exits the urethra through the penile meatus (mal ...

(greater than 2.5 L or 3 L over 24 hours in adults). Increased production and passage of urine may also be termed as

diuresis Diuresis () is the excretion of urine, especially when excessive (polyuria). The term collectively denotes the physiologic processes underpinning increased urine production by the kidneys during maintenance of fluid balance. In healthy people, ...

. Polyuria often appears in conjunction with polydipsia (increased thirst), though it is possible to have one without the other, and the latter may be a cause or an effect.

Primary polydipsia Primary polydipsia and psychogenic polydipsia are forms of polydipsia characterised by excessive fluid intake in the absence of physiological stimuli to drink. Psychogenic polydipsia caused by psychiatric disordersoftentimes schizophreniais frequ ...

may lead to polyuria. Polyuria is usually viewed as a

symptom Signs and symptoms are diagnostic indications of an illness, injury, or condition. Signs are objective and externally observable; symptoms are a person's reported subjective experiences. A sign for example may be a higher or lower temperature ...

sign A sign is an object, quality, event, or entity whose presence or occurrence indicates the probable presence or occurrence of something else. A natural sign bears a causal relation to its object—for instance, thunder is a sign of storm, or me ...

of another disorder (not a disease by itself), but it can be classed as a disorder, at least when its underlying causes are not clear.

Causes

The most common cause of polyuria in both adults and children is uncontrolled

diabetes mellitus Diabetes mellitus, commonly known as diabetes, is a group of common endocrine diseases characterized by sustained hyperglycemia, high blood sugar levels. Diabetes is due to either the pancreas not producing enough of the hormone insulin, or th ...

, which causes osmotic diuresis; when glucose levels are so high that glucose is excreted in the urine. Water follows the glucose concentration passively, leading to abnormally high urine output. In the absence of diabetes mellitus, the most common causes are the decreased secretion of

aldosterone Aldosterone is the main mineralocorticoid steroid hormone produced by the zona glomerulosa of the adrenal cortex in the adrenal gland. It is essential for sodium conservation in the kidney, salivary glands, sweat glands, and colon. It plays ...

due to adrenal cortical tumor,

primary polydipsia Primary polydipsia and psychogenic polydipsia are forms of polydipsia characterised by excessive fluid intake in the absence of physiological stimuli to drink. Psychogenic polydipsia caused by psychiatric disordersoftentimes schizophreniais frequ ...

(excessive fluid

drinking Drinking is the act of ingesting water or other liquids into the body through the mouth, proboscis, or elsewhere. Humans drink by swallowing, completed by peristalsis in the esophagus. The physiological processes of drinking vary widely among ...

central diabetes insipidus Central diabetes insipidus, recently renamed arginine vasopressin deficiency (AVP-D), is a form of diabetes insipidus that is due to a lack of vasopressin (ADH) production in the brain. Vasopressin acts to increase the blood volume, volume of bl ...

, and nephrogenic diabetes insipidus. Polyuria may also be due to various chemical substances, such as

diuretic A diuretic () is any substance that promotes diuresis, the increased production of urine. This includes forced diuresis. A diuretic tablet is sometimes colloquially called a water tablet. There are several categories of diuretics. All diuretics ...

caffeine Caffeine is a central nervous system (CNS) stimulant of the methylxanthine chemical classification, class and is the most commonly consumed Psychoactive drug, psychoactive substance globally. It is mainly used for its eugeroic (wakefulness pr ...

, and

ethanol Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...

. It may also occur after

supraventricular tachycardia Supraventricular tachycardia (SVT) is an umbrella term for fast heart rhythms arising from the upper part of the heart. This is in contrast to the other group of fast heart rhythms – ventricular tachycardia, which start within the lower cham ...

s, during an onset of

atrial fibrillation Atrial fibrillation (AF, AFib or A-fib) is an Heart arrhythmia, abnormal heart rhythm (arrhythmia) characterized by fibrillation, rapid and irregular beating of the Atrium (heart), atrial chambers of the heart. It often begins as short periods ...

childbirth Childbirth, also known as labour, parturition and delivery, is the completion of pregnancy, where one or more Fetus, fetuses exits the Womb, internal environment of the mother via vaginal delivery or caesarean section and becomes a newborn to ...

, and the removal of an obstruction within the urinary tract. Diuresis is controlled by

antidiuretic An antidiuretic is a chemical substance, substance that helps to control fluid balance in an animal's body by reducing urination, opposing diuresis. Its effects are opposite that of a diuretic. The major endogeny (biology), endogenous antidiuretics ...

s such as

vasopressin Mammalian vasopressin, also called antidiuretic hormone (ADH), arginine vasopressin (AVP) or argipressin, is a hormone synthesized from the ''AVP'' gene as a peptide prohormone in neurons in the hypothalamus, and is converted to AVP. It ...

angiotensin II Angiotensin is a peptide hormone that causes vasoconstriction and an increase in blood pressure. It is part of the renin–angiotensin system, which regulates blood pressure. Angiotensin also stimulates the release of aldosterone from the ...

and

. ''Cold diuresis'' is the occurrence of increased urine production upon exposure to cold, which also partially explains immersion diuresis. ''High-altitude diuresis'' occurs at altitudes above and is a desirable indicator of adaptation to high altitudes. Mountaineers who are adapting well to high altitudes experience this type of diuresis. People who produce less urine even in the presence of adequate fluid intake are probably not adapting well to high altitudes. Bacteriuria pyuria 4

List of causes

Mechanism

Polyuria, in osmotic cases, increases flow amount in the distal

nephron The nephron is the minute or microscopic structural and functional unit of the kidney. It is composed of a renal corpuscle and a renal tubule. The renal corpuscle consists of a tuft of capillaries called a glomerulus and a cup-shaped structu ...

where flow rates and

velocity Velocity is a measurement of speed in a certain direction of motion. It is a fundamental concept in kinematics, the branch of classical mechanics that describes the motion of physical objects. Velocity is a vector (geometry), vector Physical q ...

are low. The significant pressure increase occurring in the distal nephron takes place particularly in the cortical-collecting ducts. One study from 2008 laid out a hypothesis that hyperglycaemic and osmotic polyuria play roles ultimately in diabetic nephropathy.

Diagnosis

Among the possible tests to diagnose polyuria are:

Treatment

Depending on the cause of the polyuria, the adequate treatment should be afforded. According to

NICE Nice ( ; ) is a city in and the prefecture of the Alpes-Maritimes department in France. The Nice agglomeration extends far beyond the administrative city limits, with a population of nearly one million if other medical treatments have failed. The recommendation had no studies that met the criteria for consideration.

References

External links

{{Urinary system symptoms and signs Symptoms and signs: Urinary system Health