Which Signs and Symptoms Are Consistent With SIADH?
A low sodium level (hyponatremia) is the most common cause of symptoms associated with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). If hyponatremia develops gradually, it does not cause any noticeable symptoms. However, signs and symptoms may be prominent in severe or rapid onset of hyponatremia and can include:
- Confusion
- Disorientation
- Loss of appetite
- Muscle weakness
- Depressed mood
- Irritability
- Tremor
- Asterixis (involuntary jerking movements on extending the wrist, also called flapping tremors)
- Impaired balance or coordination
- Slurred speech
- Nausea and vomiting
- Headache
- Memory impairment
- Hallucinations
- Seizures
- Coma
- Cheyne-stokes respiration (an abnormal breathing pattern, especially during sleep)
- Hyporeflexia (a condition where the muscles have decreased or absent reflexes)
- Personality changes
- Stupor (a state in which the person is almost unconscious, and their thoughts are unclear)
| System | Signs and symptoms |
|---|---|
| General |
|
| Neurologic |
|
| Cardiovascular |
|
| Gastrointestinal |
|
| Renal |
|
| Musculoskeletal |
|
What is SIADH?
Syndrome of inappropriate secretion of antidiuretic hormone (SIADH) occurs when the body produces an excess antidiuretic hormone (ADH). ADH helps the kidney retain the appropriate amount of water. When the body produces excess ADH, it leads to more water retention and sodium level depletion (due to dilution) in the blood.
What is the most common cause of SIADH?
Syndrome of inappropriate secretion of antidiuretic hormone may be caused by the following:
- Surgery under general anesthesia
- Certain medications, such as blood pressure medications, anti-seizure medications, medications to treat type II diabetes
- Meningitis (inflammation of the membranes covering the brain and spinal cord)
- Encephalitis (inflammation of the brain)
- Brain tumors
- Psychosis
- Lung diseases, such as pneumonia, tuberculosis, cancer, or chronic infections
- Head trauma
- Hereditary causes
- Guillain–Barre syndrome (a reversible condition that affects nerves in the body)
- Acute respiratory failure
- Asthma
- Chronic obstructive lung disease
- Tuberculosis
- Cancer of the lung, small intestine, pancreas, brain, leukemia
- Hydrocephalus (fluid accumulation in the brain)
- Generalized infections, such as the human immunodeficiency virus and Rocky Mountain spotted fever
- Multiple sclerosis (a condition that involves damage of the protective covering of the nerves)
- Sarcoidosis (an inflammatory disease where lumps of inflammatory cells are formed in various organs)
When should I contact my healthcare provider?
Contact the doctor if you experience the following symptoms:
Seek immediate care or call 911 if someone has the following severe symptoms: