Normal Reference Ranges
Adult
135 - 145 mEq/L
Pediatric
135 - 145 mEq/L
Clinical Significance
Major extracellular cation. Crucial for maintaining fluid balance, nerve transmission, and muscle function. Rapid correction of chronic hyponatremia can cause osmotic demyelination syndrome.
Causes of High
- Dehydration
- Diabetes insipidus
- Cushing syndrome
- Excessive saline intake
Causes of Low
- SIADH
- Heart failure
- Cirrhosis
- Diuretics
- Vomiting/Diarrhea
- Psychogenic polydipsia