Hyponatremia can occur with hypovolemia, euvolemia, or hypervolemia depending on the balance of sodium and water in the body. With hypovolemic hyponatremia, sodium loss exceeds water loss leading to volume depletion; common causes include diuretic use, adrenal insufficiency, vomiting, and burns. Euvolemic hyponatremia results from excess water intake or retention relative to normal sodium levels, such as from overhydration during exercise or due to SIADH. Hypervolemic hyponatremia occurs when too much water is retained relative to sodium, as seen in heart failure, liver disease, or kidney disease. Sympt