hypernatremia /hī′pərnatrē″mē·ə/ [Gk, hyper + L, natrium, sodium] , a greater-than-normal concentration of sodium in the blood, caused by excessive loss of water and electrolytes that results from polyuria, diarrhea, excessive sweating, or inadequate water intake. It may also be a result of a large intake of salt, either orally or intravenously. When water loss is caused by kidney dysfunction, urine is profuse and dilute. If water loss is not through the kidneys, such as in diarrhea and excessive sweating, the urine is scanty and highly concentrated. People with hypernatremia may become mentally confused, have seizures, and lapse into coma. The treatment is restoration of fluid and electrolyte balance by mouth or by IV infusion. Care must be taken to restore water balance slowly because further electrolyte imbalances may occur and complications from correcting sodium concentration may arise. Also spelled hypernatraemia. See also diabetes insipidus.
