What is the main characteristic of oliguria?

Oliguria is defined as the production of abnormally small amounts of urine. The condition is typically characterized by urine output of less than 400 milliliters per day in adults. This state can indicate various underlying health issues, often related to kidney function, dehydration, or obstruction in the urinary tract.

The characteristic of scanty urination accurately reflects the definition of oliguria. It signifies that the body is not producing enough urine, which can be critical in diagnosing and determining the severity of conditions affecting renal function. Monitoring urine output is essential in medical settings as a decrease can suggest dysfunction that may need urgent investigation or intervention.

The other options indicate conditions that do not align with oliguria. Excessive urination describes polyuria, which is the opposite condition, while normal urination pertains to standard output levels in healthy individuals. Painless urination does not relate directly to the volume produced but rather addresses an aspect of urination that may be experienced with or without change in output.