Which statement about normal daily urine volume is true?

Which statement about normal daily urine volume is true?

• A. Avg adult output is 0.2-0.4 L/day
• B. Avg adult output is 0.5-1 L/day
• C. Avg adult output is 2-3 L/day
• D. Avg adult output is 1-2 L/day

Answer: (D)

Normal daily urine volume in a healthy adult is about 1–2 liters. This range reflects usual fluid intake and normal kidney function, with kidneys filtering a large volume but reabsorbing most of it so only about a liter or two becomes urine daily. Hormonal control (like ADH and aldosterone) helps fine-tune this to match hydration status. If fluid intake is high or kidney concentrating ability is normal, output tends toward the upper end of this range; if intake is low or there’s impaired concentrating ability, output can drop toward the lower end. The other options fall outside the typical baseline: 0.2–0.4 L/day is too low for a normally hydrated adult, and 2–3 L/day is higher than the usual normal range, though it can occur with very high fluid intake.

Normal daily urine volume in a healthy adult is about 1–2 liters. This range reflects usual fluid intake and normal kidney function, with kidneys filtering a large volume but reabsorbing most of it so only about a liter or two becomes urine daily. Hormonal control (like ADH and aldosterone) helps fine-tune this to match hydration status. If fluid intake is high or kidney concentrating ability is normal, output tends toward the upper end of this range; if intake is low or there’s impaired concentrating ability, output can drop toward the lower end. The other options fall outside the typical baseline: 0.2–0.4 L/day is too low for a normally hydrated adult, and 2–3 L/day is higher than the usual normal range, though it can occur with very high fluid intake.