Syndrome of inappropriate antidiuretic hormone secretion

Syndrome of inappropriate antidiuretic hormone secretion (SIADH or SIAD) was described in patients with lung cancer who developed hyponatremia associated with continued urinary sodium loss. The result is often dilutional hyponatremia in which the sodium remains normal but total body fluid increases.


Inappropriate (excessive) release of antidiuretic hormone (ADH), later discovered to consist of arginine-vasopressin (AVP), may be caused by: 

Treatment and prognosis

The optimal therapy for SIADH is to treat the underlying cause. If this is not possible, or if the disease has become refractory, other treatment methods are available such as water restriction, demeclocycline therapy, or in severe cases infusion of hypertonic saline together with frusemide during careful monitoring.

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Article information

rID: 29132
System: Chest, Oncology
Section: Syndromes
Synonyms or Alternate Spellings:
  • SIAD

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