The effect of high sodium on the body is mainly to cause hypernatremia, which is manifested as drowsiness, increased muscle tone, convulsions and so on. The normal blood sodium concentration of human body is 135~145mmol/L, more than 145mmol/L is hypernatremia, mainly caused by blood concentration, seen in hypertonic water loss, excessive sodium intake, traumatic brain injury and so on. It can cause neurological lesions, and can also lead to dyspnea and dyskinesia. Early manifestations of hypernatremia include dry skin, thirst, low urine output, generalized weakness, nausea, vomiting, and elevated body temperature; further development may show central nervous system manifestations, such as irritability, irritability, apathy, drowsiness, convulsions, seizures, and in severe cases, coma and even death. Hypernatremia can have complications such as acute heart failure and acute renal failure. When hypernatremia occurs, the cause should be clarified in time and treated actively.