Which term describes reduced urine output often indicating dehydration or kidney problems?

• A. Polyuria
• B. Oliguria
• C. Anuria
• D. Hematuria

Answer: (B)

Oliguria is the term for reduced urine output. It describes urine production that falls below normal, typically under about 400–500 mL in a 24-hour period in adults, or roughly 0.5 mL/kg per hour. This pattern often points to dehydration or kidney problems because decreased blood flow to the kidneys or damaged renal tissue reduces their ability to form urine. By contrast, polyuria means increased urine output, as seen with diabetes or diuretic use. Anuria is an even more extreme form, where urine production is nearly or completely absent, indicating severe kidney failure or obstruction. Hematuria refers to blood in the urine, which is about a urinary tract issue rather than a change in how much urine is produced.