Normally, ADH is secretion is triggered by high plasma osmolality or low blood volume. Often, the plasma osmolality is more dilute than the urine osmolality. In all cases, the urine osmolality is disproportionately high for a given plasma osmolality. Sodium output is higher than expected for a given plasma sodium level. A long list of possible etiologies is listed below.
Treatment usually consists of restriction of water intake to daily insensible losses .
If the patient has evidence of fluid overloading, a history of CHF, or is resistant to treatment, loop diuretics may be added as well. Chronic treatment may involve administration of lithium or demeclocycline which inhibit ADH action.