The main cause of plateau reaction is the decrease of atmospheric pressure, because after entering the high altitude area, the human body cannot adapt to the change of air pressure, so a series of plateau reactions will occur. The air pressure on the plateau is usually 1/2 of that on the plain, so the relative air pressure is relatively low and the oxygen content is relatively thin. Therefore, for patients who were not weak in the past, such as those who are physically weaker, they will experience aggravation of basic diseases and even obvious plateau reactions, such as dizziness, headache, difficulty in breathing, palpitations, fatigue, and weakness. For patients with mild symptoms, the symptoms can gradually disappear and be relieved after 3-5 days with a certain degree of oxygen intake; however, for patients with severe plateau reactions, significant plateau pulmonary edema and cerebral edema may occur.