Hypertonic dehydration is usually classified as mild, moderate or severe, and the clinical manifestations of dehydration are different at each level. First, patients with mild hypertonic dehydration have only clinical symptoms of thirst and no other clinical symptoms of the body, and the amount of water lost at this time is 2%-4% of the total body weight. Second, moderate hypertonic dehydration will have extreme thirst, accompanied by dry lips, sunken eye sockets, poor skin elasticity, and therefore irritability with peripheral weakness. The urinary system will also have low urine and high urine specific gravity, and the amount of water loss at this time is 4%-6% of the total weight. Third, the most serious dehydration is severe dehydration, in which in addition to the clinical symptoms of moderate dehydration, there are also serious neurological symptoms, such as delirium or coma, and brain dysfunction, anuria or teal urine, etc. The water deficit in this case is 6% or more of the total weight.