Hypertonic dehydration, also known as primary dehydration or hypernatremia with reduced extracellular fluid, is characterized by more water loss than sodium loss, a serum sodium concentration of 150 mmol/L, and a plasma osmolality of 310 mOsm/L. When there is more water deficiency than sodium deficiency, the osmolality of extracellular fluid increases, antidiuretic hormone secretion is increased, renal tubular reabsorption of water is increased, and urine output is decreased. Aldosterone secretion increases, and sodium and water reabsorption increases to maintain blood volume. If water deficiency continues, the osmolarity of extracellular fluid increases further, intracellular fluid moves to the extracellular level, and eventually the degree of intracellular water deficiency exceeds that of extracellular fluid deficiency, which can eventually lead to brain cell dehydration and cause brain dysfunction. Patients with more water loss than sodium loss and high serum sodium concentration should eat more fresh fruits and vegetables, and appropriately eat some apples and peaches. The following foods are recommended to eat in moderation: 1, cucumber: rich in water, and rich in fiber and vitamins, the gastrointestinal tract emptying have a very good role in promoting recovery. 2, eggplant: rich in vitamin B, has a good nutritional neurological role, is conducive to improving the function of the intestinal mucosa, promote intestinal evacuation. 3, tomatoes: rich in vitamin C, has a good role in nourishing myocardial cells, is conducive to alleviating the disease caused by the body circulation dysfunction and other symptoms of relief.