What condition is characterized by decreased urine output?

The condition characterized by decreased urine output is oliguria. Oliguria is defined as a urinary output of less than 400 milliliters per day in adults or a decrease of more than 50% from the normal urine output. It may result from various causes, including dehydration, renal failure, or urinary obstructions, leading to a significant decrease in the amount of urine produced.

Polyuria, in contrast, refers to an excessive output of urine, typically more than 3 liters per day, often seen in conditions such as diabetes mellitus. Anuria represents an even more severe decrease in urine output, defined as having less than 100 milliliters of urine in 24 hours, and can indicate severe kidney problems or complete obstruction. Hematuria is the presence of blood in the urine and does not directly relate to the volume of urine output but rather indicates blood-related urinary issues. Thus, oliguria is specifically the term used for decreased urine output.