Polyuria is:

• A. Lack of urine production
• B. Production of excessive amounts of urine
• C. Lack of water intake
• D. Excessive protein in urine

Answer: (B)

Polyuria means producing an excessive amount of urine. It refers to unusually high urine volume, not to how concentrated the urine is or what’s in it. It’s different from oliguria, which is reduced urine production, and from polydipsia, which is excessive drinking (the kidneys may produce a lot of urine as a result, but the key idea is the volume of urine). It’s also not about proteins in the urine—that would be proteinuria.

In practice, polyuria can arise from osmotic diuresis (such as excess glucose in urine in diabetes mellitus), diabetes insipidus, kidney disease, or from receiving large volumes of fluids or certain diuretics. When evaluating polyuria, clinicians assess urine volume, urine concentration (specific gravity), and accompanying signs like increased thirst to identify potential causes.