There must be harm. If you are healthy, you will get used to it. According to Jinghua Times, pilots flying at high altitude are people exposed to cosmic rays, and their health is threatened to varying degrees, but they are not included in the ranks of radiation protection management in China. Effect on the ear. When we usually live on the ground, we keep an atmospheric pressure in our human body, which is basically equal to the atmospheric pressure outside. Under normal circumstances, people will not feel any discomfort. If you catch a cold, a stuffy nose will hinder your adjustment and make people feel uncomfortable. At this time, flying in the air (or flying by plane), with the increase of altitude, the pressure difference between inside and outside increases, and the internal pressure is greater than the external pressure, which is bound to be excreted. People are used to using the nose, but due to the blockage of the nose, the internal pressure will cause the eardrum to swell, and in severe cases, it will cause congestion around the eardrum, which will thicken the eardrum and reduce hearing. Effect on the stomach. Before going to heaven, it is best not to eat beans or other foods that are easy to produce gas, otherwise it will easily cause abdominal distension and affect gastrointestinal function. People with poor gastrointestinal function may have an earlier and greater impact. This phenomenon is also caused by the change of air pressure, so we should rule out human factors in advance.