Nephrogenic diabetes insipidus differs from central diabetes insipidus in that nephrogenic DI:

Nephrogenic diabetes insipidus differs from central diabetes insipidus in that nephrogenic DI:

• A. Does Not Respond to ADH
• B. Will Eventually Resolve Without Medication
• C. Requires the Nasal Spray Lypressin
• D. Will Require Dialysis

Answer: (A)

The key idea is how the kidney responds to antidiuretic hormone (ADH). In nephrogenic diabetes insipidus, the renal tubules are insensitive to ADH, so giving ADH (or its analogs) does not reduce urine output or concentrate the urine. The kidneys fail to reabsorb water despite ADH signaling, leading to persistent polyuria and dilute urine. In contrast, central diabetes insipidus is due to ADH deficiency, so administering ADH can markedly reduce urine volume and raise urine osmolality. That difference—no response to ADH in nephrogenic DI versus a response in central DI—is what distinguishes the two. The other statements aren’t defining features: nephrogenic DI does not reliably resolve on its own and is not treated by a nasal vasopressin spray; dialysis is not a typical or initial management step for DI.

The key idea is how the kidney responds to antidiuretic hormone (ADH). In nephrogenic diabetes insipidus, the renal tubules are insensitive to ADH, so giving ADH (or its analogs) does not reduce urine output or concentrate the urine. The kidneys fail to reabsorb water despite ADH signaling, leading to persistent polyuria and dilute urine.

In contrast, central diabetes insipidus is due to ADH deficiency, so administering ADH can markedly reduce urine volume and raise urine osmolality. That difference—no response to ADH in nephrogenic DI versus a response in central DI—is what distinguishes the two.

The other statements aren’t defining features: nephrogenic DI does not reliably resolve on its own and is not treated by a nasal vasopressin spray; dialysis is not a typical or initial management step for DI.