The dry heaving caused by coughing is due to the anatomical structure of the body, because the trachea passes through the chest cavity, and side by side with it is the esophagus. The esophagus and the trachea pass parallel to each other in the chest cavity, so if you cough, when the lung gas goes up against the phlegm in the lungs, there is a strong upward flow of air that carries the entire trachea upward to discharge the phlegm. But at this time, the esophagus is not hanging in the air, there are some muscle tissues in the middle that connect them together, and when the airway rushes upward, it will definitely carry the esophagus upward. Occasionally it is not a big problem because the muscle tissue is elastic, but if you have a long cough or a violent cough too many times, it will repeatedly carry the esophagus and the whole digestive system upwards. Underneath the esophagus is the stomach, which is very large, and during repeated upward movements the stomach tends to enlarge the hole left in the diaphragm for the esophagus. Therefore, when coughing, because coughing is only for phlegm, try to help get the phlegm out, do not cough hard, it is harmful to the human body.