If the patient has chest tightness and insufficient breath: first, the disease of cardiac origin should be considered, such as coronary heart disease unstable angina pectoris, malignant arrhythmia, severe myocarditis, acute pericarditis, infective endocarditis, or heart failure, there will be chest tightness, shortness of breath, and discomfort in the precordial area. Secondly, for endocrine metabolic diseases, this clinical symptom can also be found in thyroid dysfunction and adrenocortical dysfunction. Third, if the patient has cardiac neurosis, especially in the case of vegetative nerve dysfunction, there will be this manifestation. Fourth, for the respiratory system diseases, common for chronic bronchitis, chronic bronchial dilatation, chronic obstructive pulmonary emphysema, pulmonary hypertension, pulmonary heart disease. At this time, the patient will appear arterial oxygen saturation decreased, oxygen partial pressure is low, there will also be chest tightness, shortness of breath, wheezing, self-consciousness of not enough air clinical manifestations.