What disorder is characterized by insufficient ADH activity?

The disorder characterized by insufficient antidiuretic hormone (ADH) activity is central diabetes insipidus. This condition occurs when the body does not produce adequate amounts of ADH, which plays a crucial role in regulating water balance by promoting the reabsorption of water in the kidneys. When ADH levels are low, the kidneys cannot effectively concentrate urine, leading to excessive urine output and increased thirst.

In central diabetes insipidus, this deficiency in ADH typically results from damage to the hypothalamus or pituitary gland, which can occur due to injury, disease, or genetic factors. The hallmark symptoms include copious urination (polyuria) and polydipsia, where individuals experience extreme thirst due to the loss of fluid.

Other disorders listed do not involve insufficient ADH activity. For instance, hypoparathyroidism relates to low levels of parathyroid hormone affecting calcium levels, diabetic ketoacidosis is a complication of uncontrolled diabetes related to insulin deficiency rather than ADH, and the syndrome of inappropriate ADH secretion (SIADH) involves excess ADH production leading to water retention rather than insufficient activity.