Diarrhea refers to the number of stools ≥3 times per day, accompanied by changes in stool properties, and is due to intestinal dysfunction. The common causes include mainly infectious and non-infectious diarrhea. The most harmful effects of diarrhea on the body are dehydration, electrolyte disturbance, and acid-base imbalance. Generally speaking, there are three degrees of dehydration, namely mild, moderate and severe; mild dehydration has insignificant clinical manifestations, such as mild thirst, low urination, normal skin elasticity, no mental discomfort or sunken eye sockets, and can mostly recover after oral rehydration; moderate dehydration has more obvious clinical manifestations, such as thirst, low urination, dry lips, sunken eye sockets, poor skin elasticity and even mental discomfort, and requires timely rehydration, otherwise The clinical manifestations of severe dehydration are very obvious, with severe dry mouth, little or no urine, poor spirit and obvious agitation, and even the manifestation of hypovolemic shock, such as cold extremities, fine and rapid pulse, and falling blood pressure, etc. If not treated in time, the life may be endangered in the short term, and at this time, in addition to oral rehydration, intravenous rapid rehydration is needed to restore the effective blood volume in a short time. . Therefore, once the symptoms of moderate to severe dehydration appear, it is necessary to pay attention to them and seek medical treatment in a timely manner.