A person has an elevated plasma osmolality and reduced plasma antidiuretic hormone (ADH) level and excretes a large volume of osmotically dilute urine. The urine contains no glucose. What is the most likely explanation for this situation?

Question

Quizplus · Accepted Answer

Neurogenic diabetes insipidus is characterized by a deficiency in ADH production, leading to elevated plasma osmolality, low ADH levels, and the excretion of large volumes of dilute urine. Normally an elevated plasma osmolarity will stimulate increased antidiuretic hormone secretion and cause increased renal water reabsorption which should lower the elevated plasma osmolarity. Since in this case antidiuretic hormone is reduced in the face of elevated osmolarity and the kidney is not reabsorbing water, it is clear that neurogenic diabetes insipidus is present.

A Person Has an Elevated Plasma Osmolality and Reduced Plasma