Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH)
What is syndrome of inappropriate antidiuretic hormone secretion (SIADH)?
Syndrome of inappropriate antidiuretic hormone secretion occurs when excessive levels of antidiuretic hormones (hormones that help the kidneys, and body, conserve the correct amount of water) are produced. The syndrome causes the body to retain water and certain levels of electrolytes in the blood to fall (such as sodium). SIADH is rare in children.
What causes SIADH?
SIADH tends to occur in people with heart failure or people with a diseased hypothalamus (the part of the brain that works directly with the pituitary gland to produce hormones). In other cases, a certain cancer (elsewhere in the body) may produce the antidiuretic hormone, especially certain lung cancers. Other causes may include the following:
Meningitis (inflammation of the meninges, the membranes that cover the brain and spinal cord)
Encephalitis (inflammation of the brain)
Guillain-Barré syndrome (a reversible condition that affects the nerves in the body. GBS can result in muscle weakness, pain, and even temporary paralysis of the facial, chest, and leg muscles. Paralysis of the chest muscles can lead to breathing problems.)
Damage to the hypothalamus or pituitary gland during surgery
Thyroid or parathyroid hormone deficiencies
What are the symptoms of SIADH?
Each person may experience symptoms differently. Symptoms, in more severe cases of SIADH, may include:
Nausea or vomiting
Cramps or tremors
Depressed mood,memory impairment
Personality changes, such as combativeness, confusion, and hallucinations
Stupor or coma
The symptoms of SIADH may resemble other problems or medical conditions. Always consult your child's doctor for a diagnosis.
How is SIADH diagnosed?
In addition to a complete medical history and physical examination, to confirm diagnosis of SIADH, blood and urine tests will need to be performed to measure sodium, potassium, and osmolality (concentration of solution in the blood and urine).
Treatment for SIADH
Specific treatment for SIADH will be determined by your doctor based on:
Your age, overall health, and medical history
Extent of the disease
Your tolerance for specific medications, procedures, or therapies
Expectations for the course of the disease
Your opinion or preference
The most commonly prescribed treatment for SIADH is fluid and water restriction. If the condition is chronic, fluid restriction may need to be permanent. Treatment may also include:
Certain medications that inhibit the action of ADH (also called vasopressin)
Surgical removal of a tumor that is producing ADH
Other medicines to help regulate body fluid volume