Syndrome of Inappropriate Antidiuretic Hormone Secretion

Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a rare condition that occurs when your child’s body produces too much antidiuretic hormone (ADH). ADH helps regulate the amount of water in the body. In SIADH, the body retains too much water, which leads to low sodium levels in the blood.

What Causes SIADH?

SIADH may be caused by:

• Injury to the head or brain that affects the thalamus (which helps regulate hormones)
• Damage to the hypothalamus or pituitary gland during surgery
• Meningitis or encephalitis (types of inflammation affecting the brain)
• Brain tumor
• Low thyroid or parathyroid hormones
• Lung disease
• Guillain-Barré syndrome
• HIV
• Certain medicines
• Genetic causes
• Psychosis

Symptoms of SIADH

The symptoms of SIADH may be different for each child. Your child may experience:

• Headache
• Nausea or vomiting
• Cramps or tremors
• Irritability or depression
• Anger or confusion
• Memory problems
• Seizures
• Hallucinations
• Coma

Diagnosis & Treatment

At UVA Health Children's, your child’s doctor may perform or recommend:

• Blood test
• Urine test
• Measurement of sodium level
• Measurement of potassium level

Children with SIADH may need to limit the amount of fluid they drink. Treatment may also include:

• Medications to block ADH
• Surgery (if appropriate)
• Medications to control body fluid levels