Syndrome of inappropriate antidiuretic hormone (SIADH)

Definition

Syndrome of inappropriate antidiuretic hormone (SIADH) is a condition where the body secretes excessive antidiuretic hormone (ADH), leading to water retention and hyponatremia. It disrupts the balance of fluids and electrolytes in the body.

5 Must Know Facts For Your Next Test

1. SIADH results in dilutional hyponatremia due to water retention.
2. Common causes include brain injury, lung disease, and certain medications.
3. Symptoms can range from mild (nausea, headache) to severe (confusion, seizures).
4. Treatment often involves fluid restriction and administration of hypertonic saline or ADH antagonists.
5. Lab findings typically show low plasma osmolality and high urine osmolality.

Review Questions

• What are the common symptoms associated with SIADH?
• Which lab findings are indicative of SIADH?
• What is the primary treatment approach for managing SIADH?

Related terms

Antidiuretic Hormone (ADH): A hormone that helps regulate water balance by increasing water reabsorption in the kidneys.

Hyponatremia: A condition characterized by low sodium levels in the blood.

Hypertonic Saline: A high-concentration salt solution used to treat severe hyponatremia.