Shortness of breath, shortness of breath, difficulty in breathing, chest tightness, not enough air, etc., all refer to the feeling that normal breathing cannot meet the body’s demand for oxygen intake, thus producing shortness of breath and not enough air. In addition to the expressions of shortness of breath, shortness of breath, difficulty in breathing, chest tightness, gas utterance, and insufficient gas, there are other expressions in dialects, such as Shanghai people say: gas utterance, Shandong say: backboard. In short, they all express the feeling of not having enough air. There are various reasons for this symptom: pneumothorax, worsening of chronic obstructive pulmonary disease, pulmonary embolism, asthma, coronary heart disease, and neuromuscular diseases. The most common are diseases of the heart and lungs. When these symptoms occur, it is best to seek urgent medical attention to identify the cause and treat it promptly. Note: Delay can be life-threatening.