What does oliguria refer to?

Oliguria refers to a condition characterized by scanty or reduced urinary output. It indicates that the kidneys are producing a lower-than-normal volume of urine, often defined as less than 400 milliliters per day in adults. This can be a sign of various underlying health issues, such as dehydration, kidney problems, urinary tract obstructions, or heart failure.

The other terms in the question refer to different urinary conditions. Nocturia describes excessive urination at night, hematuria refers to the presence of blood in the urine, and anuria denotes the complete absence of urine output. Understanding these definitions helps differentiate between various urinary symptoms and their associated health implications.