Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH)

Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) is a disorder of fluid and electrolyte balance in which antidiuretic hormone (ADH) is inappropriately secreted. ADH normally helps the kidneys regulate water balance in the body by helping them conserve water. In SIADH, the body retains too much water, which causes the body to have too little sodium, leading to symptoms such as a low blood pressure, confusion, fatigue, muscle weakness, and convulsions.

SIADH is typically caused by an underlying condition such as a brain tumor, stroke, head trauma, pneumonia, or a medication side effect. It is most common in the elderly, but can affect people of any age. Treatment for SIADH usually involves treating the underlying cause, if possible, and managing symptoms with medications or fluids.

Signs and Symptoms of SIADH

Low levels of sodium in the blood (hyponatremia)
Excessive urination (polyuria)
Excessive thirst (polydipsia)
Headache
Confusion
Fatigue
Muscle weakness
Nausea
Loss of appetite
Numbness and tingling
Convulsions

Treatment of SIADH

The treatment of SIADH is focused on managing symptoms and correcting electrolyte imbalances. Treatment also involves treating the underlying cause, when possible. Depending on the individual’s underlying condition, treatment may include:

Medications to regulate ADH levels
Diuretics to increase sodium levels
Fluids to restore electrolyte balance
Surgery to remove a tumor, if present
IV fluids to restore fluid and electrolyte balance

It is important to consult with a doctor before beginning any treatment for SIADH. Treatment should be based on each individual’s unique medical history, and the underlying condition causing SIADH should be treated as quickly as possible.