High electrolyte sodium is defined as serum sodium ions above 145 mmol/L and is called hypernatremia. It can be classified as concentrated hypernatremia, retained sodium hypernatremia, and idiopathic hypernatremia. Common causes include blood concentration, reduced renal sodium excretion, and excessive sodium intake. 1. Concentrative hypernatremia: due to excessive water loss, more water loss than sodium loss, seen in hyperosmolar water loss due to various reasons, is the main cause of hypernatremia. 2. Sodium retention hypernatremia: mainly due to the decrease of renal sodium excretion or excessive sodium intake, such as primary aldosteronism, cortisolism, excessive sodium intake, cirrhosis of the liver with ascites, acute and chronic renal failure, cerebral trauma, cerebrovascular accidents, pituitary tumors, and other brain pathologies caused by sodium retention. 3. Idiopathic hypernatremia:It is due to the increased osmotic threshold of vasopressin release, resulting in body fluids have been in a hypertonic state. Electrolyte sodium high should be timely to the hospital, further improve the examination to clarify the cause, under the guidance of the doctor treatment.