What happens when I feel air inside my chest cavity? With air in the chest, we may feel chest tightness, shortness of breath, tightness, and difficulty breathing. If this happens, we consider several things: Is there a pneumothorax? Is it caused by a pleural effusion? Is it caused by pneumonia, obstructive lung disease? To find out the cause, we have to do some relevant tests, such as pneumothorax, pleural effusion or obstructive lung disease, we check the DR of the chest or CT of the chest, we can know what is probably the cause. If none of these causes, the feeling of air inside the chest cavity, consider the emotional causes, adjust the mind, relax the mood, it is estimated that slowly will feel smooth, if necessary, consult the psychology department, to give a detailed psychological assessment, a clear diagnosis to give targeted treatment.