hyponatremia /hī′pōnatrē″mē·ə/ [Gk, hypo + L, natrium, sodium; Gk, haima, blood] , a lower-than-normal concentration of sodium in the blood, caused by inadequate excretion of water or by excessive water in the circulating bloodstream. In a severe case the person may experience water intoxication, with confusion and lethargy, leading to muscle excitability, convulsions, and coma. Fluid and electrolyte balance may be restored by IV infusion of a balanced solution or a fluid-restricted diet. Also spelled hyponatraemia.
