Syndrome of Inappropriate Antidiuretic Hormone (SIADH): Symptoms & Signs

Medically Reviewed on 9/10/2019

Syndrome of inappropriate antidiuretic hormone (SIADH) is a condition characterized by an excess of antidiuretic hormone, leading to water retention and a low blood sodium level. Antidiuretic hormone is normally released by the pituitary gland in the brain. In this condition, an abnormal amount of the hormone is released.

Symptoms and signs of SIADH can include nausea, vomiting, fatigue, tremor, irritability, headache, muscle weakness, and cramping. Other associated symptoms can include mental changes like confusion, depressed mood, personality changes, hallucinations, memory problems, stupor, or coma.

Causes of syndrome of inappropriate antidiuretic hormone (SIADH)

Many different diseases and conditions can cause SIADH. Examples of causes include pain, exercise, heart conditions, kidney disorders, thyroid disorders, stress, brain tumors, endocrine or hormonal disorders, AIDS, infections, and taking certain medications, among many others.

Other siadh symptoms and signs

Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.