Which assessment finding is most characteristic of diabetes insipidus?

• A. Decreased urine output
• B. Increased skin turgor
• C. Increased urine output
• D. Weight gain

Answer: (C)

Diabetes insipidus causes the kidneys to lose the ability to concentrate urine because there isn’t enough antidiuretic hormone or the kidneys don’t respond to it. The result is polyuria—producing large amounts of dilute urine. Clinically, the most characteristic finding is increased urine output, often with polydipsia as the patient tries to keep up with fluid losses. The urine is dilute (low osmolality and low specific gravity), and dehydration can follow if fluid intake doesn’t match losses. Weight loss can occur from fluid loss. Increased skin turgor or weight gain would not fit this picture, as DI drives fluid loss and dehydration rather than fluid retention or overhydration.