There are many causes of chest tightness and breathlessness. Firstly, chronic bronchitis, chronic obstructive pulmonary emphysema, lung infection, pneumothorax, lung cancer and other lung diseases need to be excluded. Secondly, heart disease can also cause chest tightness and breathlessness. 1, pulmonary causes: more common chronic bronchitis, chronic obstructive pulmonary emphysema, lung infection, spontaneous pneumothorax, lung cancer, etc. Pulmonary infections such as lobar pneumonia can lead to solid lung changes; spontaneous pneumothorax can cause the lung to be squeezed and reduced due to the disappearance of negative chest pressure; lung tumors can cause partial airway obstruction to produce symptoms of chest tightness and breathlessness. It can be clarified by chest X-ray, lung CT, bronchoscopy and other examinations. 2, heart causes: more common is coronary heart disease. Coronary heart disease is more likely to occur in people over 40 years of age, and postmenopausal women have a higher risk of developing coronary heart disease. If there is a previous history of coronary heart disease, the sudden appearance of unexplained chest tightness and breathlessness may be related to the occurrence of acute myocardial infarction. Another relatively common cause is viral myocarditis, which damages myocardial structure and function due to the direct action of a virus or a combination of the virus and the immune response of the muscle. Cardiac enzymes, troponin, electrocardiogram, echocardiogram, chest X-ray, coronary CT, cardiac MRI or coronary angiogram can be used to definitively rule out cardiac problems. Heart failure is also a cause of chest tightness and breathlessness. When the decline in heart function is severe, manifestations such as exertional dyspnea and telangiectatic breathing may occur. 3, cardiac neurosis: after cardiopulmonary function tests still can not find organic lesions, then you need to consider cardiac neurosis. Cardiac neurosis is most often seen in women aged 20 to 40 years old, especially menopausal women. There is no pathological evidence of organic heart disease. Symptoms are varied and can include chest tightness, poor breathing, often feeling that there is not enough air to open the window or asking for oxygen, and many patients often do deep breathing or sigh-like breathing movements to relieve symptoms, leading to hyperventilation, causing respiratory alkalosis and worsening symptoms. You can go to the cardiosomatic medicine clinic for further consultation and treatment. Chest tightness and breath-holding may be related to impaired cardiopulmonary function and requires immediate medical attention to rule out the possibility of life-threatening etiology.