Which best describes the typical clinical presentation of diabetes insipidus?

Which best describes the typical clinical presentation of diabetes insipidus?

• A. Sweating and hypoglycemia episodes
• B. Weight gain and edema
• C. Thirst and urination with dilute urine (urine specific gravity < 1.005)
• D. Urinary ketones with metabolic acidosis

Answer: (C)

Diabetes insipidus is defined by excessive urine production and thirst because the kidneys can’t concentrate urine. When antidiuretic hormone (vasopressin) is deficient or the kidneys don’t respond to it, large volumes of very dilute urine are produced. That’s why the hallmark presentation is thirst and urination with dilute urine, with a urine specific gravity typically less than 1.005. If water intake doesn’t keep up, patients can become hypernatremic due to free-water loss. The other options don’t fit this picture: sweating with hypoglycemia points to glucose problems rather than vasopressin issues; weight gain and edema suggest fluid retention or other conditions, not DI; urinary ketones with metabolic acidosis is characteristic of diabetic ketoacidosis, not DI. So the best description is polyuria with polydipsia and dilute urine due to impaired water reabsorption in the collecting ducts.

Diabetes insipidus is defined by excessive urine production and thirst because the kidneys can’t concentrate urine. When antidiuretic hormone (vasopressin) is deficient or the kidneys don’t respond to it, large volumes of very dilute urine are produced. That’s why the hallmark presentation is thirst and urination with dilute urine, with a urine specific gravity typically less than 1.005. If water intake doesn’t keep up, patients can become hypernatremic due to free-water loss.

The other options don’t fit this picture: sweating with hypoglycemia points to glucose problems rather than vasopressin issues; weight gain and edema suggest fluid retention or other conditions, not DI; urinary ketones with metabolic acidosis is characteristic of diabetic ketoacidosis, not DI.

So the best description is polyuria with polydipsia and dilute urine due to impaired water reabsorption in the collecting ducts.