Hypernatremia is defined as a concentration of sodium ions in the serum higher than 145 mmol/L, while common clinical hypernatremia refers to concentrated hypernatremia caused by water loss and sodium loss due to various reasons, and when more water is lost than sodium is lost, resulting in blood concentration. In addition, sodium retention hypernatremia and idiopathic hypernatremia, of which idiopathic hypernatremia is the least symptomatic. Concentrated hypernatremia increases with the degree of dehydration, and clinical manifestations include dry skin, decreased elasticity, thirst, severe dry mouth affecting swallowing, insufficient effective circulation, rapid heartbeat, dizziness, weakness and irritability, etc. Whether concentrated hypernatremia or sodium retention hypernatremia, both aggravated conditions mostly cause brain cells to lose water, manifesting neurological symptoms, patients are irritable, mentally unstable, convulsions, convulsions, and in severe cases coma or even death.