Which statement about nocturnal polyuria is true?

• A. Excessive urine production at night contributes to nocturia
• B. Nocturnal polyuria occurs due to dehydration
• C. It is unrelated to sleep disorders
• D. It is diagnosed only with biopsy

Answer: (A)

Nocturnal polyuria happens when the body makes an abnormally large amount of urine during the night, which leads to waking up to urinate. That nighttime urine production is what drives nocturia, so the statement that excess nighttime urine production contributes to nocturia is the true one.

Dehydration isn’t the cause here; it tends to reduce overall urine output, not create high nighttime production. Sleep disorders can actually be linked to nocturnal polyuria—for example, sleep apnea can increase nighttime urine through mechanisms like natriuresis during sleep—so saying it’s unrelated isn’t accurate. And biopsy isn’t how this condition is diagnosed; it’s usually assessed with urinary diaries and measurements of nighttime versus total 24-hour urine output, not tissue testing.