What condition results from a deficiency of antidiuretic hormone (ADH)?

A deficiency of antidiuretic hormone (ADH) leads to diabetes insipidus, a condition characterized by the kidneys' inability to concentrate urine, resulting in excessive urination and increased thirst. ADH, also known as vasopressin, plays a critical role in regulating the body’s fluid balance by promoting water reabsorption in the kidneys.

When there is insufficient ADH, the kidneys allow more water to be excreted in the urine, which dilutes the blood and can lead to symptoms such as polyuria (large volumes of urine), polydipsia (excessive thirst), and potentially dehydration if not adequately managed.

In contrast, diabetes mellitus is associated with insulin deficiency or resistance, which affects blood sugar levels rather than fluid balance. Hypernatremia refers to elevated sodium levels in the blood, which can occur as a result of the water loss seen in diabetes insipidus but is not directly indicative of ADH deficiency itself. Hyperglycemia is elevated blood glucose levels, typically associated with diabetes mellitus and not directly related to ADH function. Thus, the primary condition stemming directly from an inadequate amount of ADH is diabetes insipidus.