Oliguria

Oliguria is defined as a urine output of less than 400 millilitres per day in adults, indicating reduced kidney function or fluid status. It is clinically significant as it can signal acute kidney injury, dehydration, or urinary obstruction, necessitating prompt evaluation and management to prevent further renal damage. A key association is acute tubular necrosis, which can arise from ischaemia or nephrotoxins, highlighting the need for timely intervention.