SIADH

Full Definition

Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a condition characterized by excessive release of ADH despite normal or low plasma osmolality, leading to water retention and dilutional hyponatremia. SIADH can result from various causes including malignancies, central nervous system disorders, pulmonary diseases, and certain medications. The condition is diagnosed through specific laboratory criteria including low serum osmolality, inappropriately concentrated urine, and normal kidney and adrenal function. Treatment typically involves fluid restriction and addressing the underlying cause.

Usage

Usage note: Always spell out on first use; commonly pronounced as an acronym rather than individual letters.

In Context

• "The patient developed SIADH secondary to small cell lung carcinoma." — Oncology consultation
• "Laboratory findings were consistent with SIADH, showing serum sodium of 125 mEq/L with concentrated urine." — Clinical assessment