Serum sodium is the concentration of sodium ions in the blood serum. The measurement of serum sodium has important clinical significance and is especially helpful in the treatment of dehydration. The normal value of serum sodium:135 – 148 mmol/L. The total amount of sodium in the organism is increased and higher than the normal range. The following is a brief introduction to prevent the increase of serum sodium. 1, the input fluid tensor should not be too low. 2, can supply part of the potassium salt which can not only improve the osmotic pressure of the input fluid without increasing the sodium load but also potassium can enter the cells to facilitate the correction of intracellular dehydration. 3, the infusion rate should not be too fast. Excessive sodium is often complicated by other diseases, such as burns, cranio-cerebral injury, COPD, liver transplantation, hyperadrenocorticism, etc. Therefore, attention should be paid to prevent electrolyte disorders when treating these diseases. Patients with symptoms of this disease should be treated promptly to prevent further development and complications of more serious diseases. In the early stage, once hypernatremia is detected, all sodium-containing fluids should be stopped immediately and infused with hypotonic fluids instead; for those who cannot drink by mouth, a gastric tube can be left in place and warm water can be dripped continuously to relieve hypernatremia and promote sodium excretion; actively control infection and lower temperature; monitor blood glucose and actively control blood glucose to normal range; after the edema period, hypertonic diuretics can be stopped if the condition allows. Most patients can get better results with the above treatment, and can effectively prevent further development of the disease.