What are the mortality and morbidity associated with oliguria?

Oliguria is the medical term for very low urine output. In adults, it is defined as urinating less than about one-and-three-quarters cup a day. Oliguria will happen if someone becomes dehydrated because the kidneys will conserve water. But oliguria can also be a sign of acute kidney injury or kidney failure. Oliguria not rapidly resolved by drinking more fluids requires immediate medical attention to help preserve kidney function.