High altitude sickness is also known as plateau reaction, which may cause diarrhea. Plateau reaction refers to a series of symptoms caused by ultraviolet radiation, dry air, cold and other climatic changes in the body after entering a high altitude area, which makes it difficult to adapt to such an environment. Plateau reaction can appear nausea, vomiting, dizziness, chest tightness, palpitations, loss of appetite and other symptoms, because at this time the patient’s gastrointestinal function will also be affected by a certain degree of diarrhea symptoms. However, diarrhea after changing the environment may also be caused by the water and soil discomfort or eat unclean food caused by acute gastroenteritis. Patients with diarrhea and plateau reaction need to be given oxygen and rest immediately, and those with severe symptoms need to go to the hospital.