SIADH (Syndrome of Inappropriate ADH)

SIADH (syndrome of inappropriate antidiuretic hormone) is a condition in which the body releases too much ADH, causing water retention and low sodium (hyponatremia).

Table of Contents

Quick Facts

  • ICD-10: E22.2

Common Causes

  • Medications (SSRIs, carbamazepine, chemo agents, others)
  • CNS disorders (stroke, meningitis, hemorrhage, head injury)
  • Lung disease (pneumonia, small cell lung cancer)
  • Cancers, especially small cell lung cancer
  • Postoperative state

Symptoms

  • Often asymptomatic if sodium is only mildly low
  • Headache, confusion, nausea
  • Lethargy, weakness
  • Seizures and coma in severe hyponatremia

Treatment

  • Fluid restriction
  • Treat underlying cause; stop offending medications
  • Salt tablets or vaptans in selected cases
  • Hypertonic saline for severe symptomatic hyponatremia (cautiously)
Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about a medical condition. If you are experiencing a medical emergency, call your local emergency number immediately.

References

  • Endocrine Society. Hyponatremia Resources.