Patients such as chest tightness, shortness of breath in the recent past: first, to consider whether there is a cardiac disease, for coronary heart disease unstable angina, myocarditis, pericarditis, rheumatic heart disease, cardiac valve disease, severe malignant arrhythmia, or patients with heart failure, there will be chest tightness, shortness of breath clinical symptoms. Second, for respiratory diseases, in chronic bronchitis, bronchial asthma, bronchodilatation, chronic obstructive pulmonary disease, pulmonary hypertension, pulmonary heart disease, there will be a decrease in blood oxygen saturation, oxygen partial pressure is too low, there will also be chest tightness, shortness of breath, palpitations due to itching. Third, for patients with vegetative nerve function disorder, especially in cardiac neurosis, the above symptoms will also appear. Fourth, if the patient has endocrine metabolic diseases, thyroid dysfunction can also lead to chest tightness and shortness of breath.