What is the primary sign of diabetes insipidus?

What is the primary sign of diabetes insipidus?

• A. High urine output (>3 L/day)
• B. Low urine output
• C. Hyponatremia
• D. Hypokalemia

Answer: (A)

In diabetes insipidus the key idea is the body’s inability to concentrate urine because there isn’t enough antidiuretic hormone or the kidneys don’t respond to it. The most noticeable sign is profuse urination. Patients typically produce a large volume of urine, often more than 3 liters in 24 hours, and the urine is dilute. This low concentration happens because the collecting ducts aren’t reabsorbing water without ADH signal. As a result, you’ll also see thirst from the water loss, and if water intake doesn’t keep up, serum sodium can rise (hypernatremia). Hyponatremia or hypokalemia aren’t characteristic signs here, and reduced urine output would point away from DI. So the best answer is the large, dilute urine output.

In diabetes insipidus the key idea is the body’s inability to concentrate urine because there isn’t enough antidiuretic hormone or the kidneys don’t respond to it. The most noticeable sign is profuse urination. Patients typically produce a large volume of urine, often more than 3 liters in 24 hours, and the urine is dilute. This low concentration happens because the collecting ducts aren’t reabsorbing water without ADH signal. As a result, you’ll also see thirst from the water loss, and if water intake doesn’t keep up, serum sodium can rise (hypernatremia). Hyponatremia or hypokalemia aren’t characteristic signs here, and reduced urine output would point away from DI. So the best answer is the large, dilute urine output.