Also Known As: Decreased urination, Oliguria, Hypouresis, Decreased urinary output
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 100 ml/day but less than 400ml/day. The decreased output of urine may be a sign of dehydration, renal failure, hypovolemic shock, HHNShyperosmolar Hyperglycemic Nonketotic Syndrome, multiple organ dysfunction syndrome, urinary obstruction/urinary retention, DKA, pre-eclampsia, and urinary tract infections, among other conditions.
Oliguria is defined as a urine output that is less than 1 mL/kg/h in infants, less than 0.5 mL/kg/h in children, and less than 400 mL or 500 mL 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/hour/kg. Alternatively, however, the value of 0.5 mL/kg/h is commonly used to define oliguria in adults as well.
Olig- (or oligo-) is a Greek prefix meaning small or few.
Anuria is defined as less than 50mL urine output per day.