What is the term for a diminished amount of urine formation?

Oliguria is the term used to describe a state of diminished urine formation, typically defined as a urinary output of less than 400 milliliters per day in adults. This condition can arise from various factors including dehydration, kidney impairment, or obstruction of urine flow. Understanding oliguria is essential in the medical field, especially in contexts involving kidney function and fluid balance in patients.

In contrast, anuria refers to an even more severe condition where there is an absence of urine production, usually resulting in a urinary output of less than 100 milliliters per day. Polyuria indicates an increased urine production, often related to conditions such as diabetes, while hematuria refers to the presence of blood in the urine. These terms denote different aspects of urinary and renal function, making it clear that oliguria specifically addresses the reduction in urine formation.