Oliguria or hypouresis is the low output 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 ...

specifically more than 80 ml/day but less than 400ml/day. The decreased output of urine may be a sign of

dehydration In physiology, dehydration is a lack of total body water that disrupts metabolic processes. It occurs when free water loss exceeds intake, often resulting from excessive sweating, health conditions, or inadequate consumption of water. Mild deh ...

kidney failure Kidney failure, also known as renal failure or end-stage renal disease (ESRD), is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney fa ...

hypovolemic shock Hypovolemic shock is a form of Shock (circulatory), shock caused by severe hypovolemia (insufficient blood volume or extracellular fluid in the body). It can be caused by severe dehydration or blood loss. Hypovolemic shock is a medical emergency ...

, hyperosmolar hyperglycemic nonketotic syndrome (HHNS),

multiple organ dysfunction syndrome Multiple organ dysfunction syndrome (MODS) is altered organ function in an acutely ill patient requiring immediate medical intervention. There are different stages of organ dysfunction for certain different organs, both in acute and in chronic ...

, urinary obstruction/

urinary retention Urinary retention is an inability to completely empty the bladder. Onset can be sudden or gradual. When of sudden onset, symptoms include an inability to urinate and lower abdominal pain. When of gradual onset, symptoms may include urinary incont ...

, diabetic ketoacidosis (DKA),

pre-eclampsia Pre-eclampsia is a multi-system disorder specific to pregnancy, characterized by the new onset of hypertension, high blood pressure and often a significant amount of proteinuria, protein in the urine or by the new onset of high blood pressure a ...

, and

urinary tract infection A urinary tract infection (UTI) is an infection that affects a part of the urinary tract. Lower urinary tract infections may involve the bladder (cystitis) or urethra (urethritis) while upper urinary tract infections affect the kidney (pyel ...

s, among other conditions. Beyond oliguria is

anuria Anuria is nonpassage of urine, in practice is defined as passage of less than 100 milliliters of urine in a day. Anuria is often caused by failure in the function of kidneys. It may also occur because of some severe obstruction like kidney stone ...

, which represents an absence of urine, clinically classified as below 80 or 100 ml/day. The term oliguria is derived from ''oligo''-meaning "small, little," + -''uria'', from the Greek word ''ouron,'' meaning ''"''urine".

Definition

Oliguria is defined as a urine output that is less than 1 mL/kg/h in infants,Free Full Text
less than 0.5 mL/kg/h in children, and less than 400 mL or 500 mL
Last full review/revision March 2009 by Soumitra R. Eachempati per 24h in adults - this equals 17 or 21 mL/hour. For example, in an adult weighing 70 kg it equals 0.24 or 0.3 mL/kg/h. Alternatively, however, the value of 0.5 mL/kg/h is commonly used to define oliguria in adults as well.

Diagnostic approach

Perform ultrasound examination of the kidney to rule out obstructive processes. The mechanisms causing oliguria can be categorized globally in three different categories: * Prerenal: in response to

hypoperfusion Perfusion is the passage of fluid through the circulatory system or lymphatic system to an organ or a tissue, usually referring to the delivery of blood to a capillary bed in tissue. Perfusion may also refer to fixation via perfusion, used in ...

of the kidney (e.g. as a result of

by poor oral intake,

cardiogenic shock Cardiogenic shock is a medical emergency resulting from inadequate blood flow to the body's organs due to the dysfunction of the heart. Signs of inadequate blood flow include low urine production (<30 mL/hour), cool arms and legs, and decreased ...

diarrhea Diarrhea (American English), also spelled diarrhoea or diarrhœa (British English), is the condition of having at least three loose, liquid, or watery bowel movements in a day. It often lasts for a few days and can result in dehydration d ...

, G6PD deficiency, massive

bleeding Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethr ...

sepsis Sepsis is a potentially life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage of sepsis is followed by suppression of the immune system. Common signs and s ...

) * Renal: due to kidney damage (severe

, rhabdomyolysis,

medication Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug or simply drug) is a drug used to medical diagnosis, diagnose, cure, treat, or preventive medicine, prevent disease. Drug therapy (pharmaco ...

) * Postrenal: as a consequence of obstruction of the urine flow (e.g.

enlarged prostate Benign prostatic hyperplasia (BPH), also called prostate enlargement, is a noncancerous increase in size of the prostate gland. Symptoms may include frequent urination, trouble starting to urinate, weak stream, inability to urinate, or lo ...

, tumour compression urinary outflow, expanding

hematoma A hematoma, also spelled haematoma, or blood suffusion is a localized bleeding outside of blood vessels, due to either disease or trauma including injury or surgery and may involve blood continuing to seep from broken capillaries. A hematoma is ...

or fluid collection)

Postoperative oliguria

Patients usually have a decrease in urine output after a major operation that may be a normal physiological response to: * fluid/ blood loss – decreased glomerular filtration rate secondary to hypovolemia and/or hypotension * response of adrenal cortex to stress-increase in

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 ...

(Na and water retention) and

antidiuretic hormone 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 ...

(ADH) release

Babies

Oliguria, when defined as less than 1 mL/kg/h, in

infant In common terminology, a baby is the very young offspring of adult human beings, while infant (from the Latin word ''infans'', meaning 'baby' or 'child') is a formal or specialised synonym. The terms may also be used to refer to juveniles of ...

s is not attributed to

References

External links