What is "oliguria"

1843, from oligo- "small, little," + -uria, from Greek ouron "urine" (see urine).

n. (context medicine English) A decreased production in the volume of urine.

1. n. abnormally small production of urine; can be a symptom of kidney disease or obstruction of the urinary tract or edema or an imbalance of fluids and electrolytes in the body

2. production of an abnormally small amount of urine

Oliguria or hypouresis (both names from roots meaning "not enough urine") is the low output of urine. In humans, it is clinically classified as an output more than 80 ml/day but less than 400ml/day. The decreased output of urine may be a sign of dehydration, kidney failure, hypovolemic shock, HHNS hyperosmolar Hyperglycemic Nonketotic Syndrome, multiple organ dysfunction syndrome, urinary obstruction/ urinary retention, DKA, pre-eclampsia, and urinary tract infections, among other conditions.

Beyond oliguria is anuria, which represents an absence of urine, clinically classified as below 80 or 100 ml/day.