What is altitude sickness and symptoms

Altitude sickness is to reach a certain altitude, the body to adapt to the altitude caused by the pressure difference, about 3700 meters above sea level, there will be altitude sickness. Plateau reaction symptoms are generally manifested as: headache, shortness of breath, chest tightness, anorexia, micro-burning, dizziness, fatigue and so on. Some people due to the lack of oxygen and the emergence of: lips and fingertips purple, lethargy, mental excitement, sleep and other different performance. Some people because of air drying and the emergence of: rough skin, chapped lips and so on.