Pituitary Disorders USMLE Step 1 Practice Question
A 24 year old man is brought to the emergency department after a motorcycle crash. Two days later he develops intense thirst and passes large volumes of dilute urine. Serum sodium is 151 mEq per L, serum osmolality is increased, and urine osmolality is low. Which of the following is the most likely cause of this patient's new condition?
Answer choices
- AResistance to parathyroid hormone in the renal tubule
- BIncreased aldosterone secretion
- CExcess atrial natriuretic peptide release
- DLoss of vasopressin secretion from the posterior pituitaryCorrect answer
- EOsmotic diuresis from uncontrolled diabetes mellitus
- FNephrogenic diabetes insipidus from renal ADH resistance
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