What is the consequence of excessive ADH secretion in non-cancer patients?

Excessive secretion of antidiuretic hormone (ADH), also known as vasopressin, leads to increased water reabsorption in the kidneys. This process occurs in the collecting ducts, where ADH promotes the insertion of aquaporin-2 water channels into the luminal membrane, allowing more water to be reabsorbed into the bloodstream. Consequently, this leads to water retention.

As water is retained in the body, it dilutes the serum sodium concentration, resulting in dilutional hyponatremia. This occurs because the total body water increases while the sodium level remains relatively unchanged, leading to a decreased serum sodium concentration.

The other options are not correct as they do not reflect the physiological consequences of excess ADH secretion accurately. Increased urine output would actually occur with insufficient ADH, while dehydration would be a result of low ADH levels. Hypervolemia can occur as a consequence of excessive water retention, but it is a downstream effect rather than the direct consequence being asked for. Thus, the most accurate description of the consequence of excessive ADH secretion is water retention and dilutional hyponatremia.