What is commonly defined as decreased urine elimination down to 400-500ml?

The definition of oliguria refers to a reduced urine output, typically quantified as producing between 400 and 500 milliliters of urine in a 24-hour period. This condition often signals an underlying issue with kidney function, which may result from various factors including dehydration, acute kidney injury, or obstruction.

In contrast, anuria, which is the production of less than 100 milliliters of urine per day, reflects a more severe state of renal dysfunction. Normal urine output usually ranges from about 800 to 2,000 milliliters per day, depending on factors such as fluid intake and hydration status. Lastly, polyuria is characterized by an excessive urine output, often exceeding 3,000 milliliters per day, which may occur in conditions such as diabetes mellitus or diabetes insipidus. Thus, oliguria is the correct term for decreased urine elimination to the specified range of 400-500 milliliters.