If the patient has chest tightness, weakness and drowsiness, the following points should be considered: First, consider cardiogenic diseases, such as coronary artery disease unstable angina, acute myocarditis, or pericarditis, heart valve disease, hypertensive heart disease, chronic heart failure, these conditions can lead to coronary artery ischemia, stenosis, insufficient blood supply, oxygen supply and cause the patient to appear lack of oxygen triggering symptoms of weakness and drowsiness. Secondly, for respiratory system diseases, chronic bronchitis, chronic bronchial dilatation, chronic pulmonary heart disease, pulmonary hypertension, chronic obstructive pulmonary emphysema, these conditions will lead to a decrease in blood oxygen saturation, low partial pressure of oxygen and high partial pressure of carbon dioxide, and therefore drowsiness will occur. Third, for patients with ionic disorders will also have the above symptoms, for example, when hypokalemia and hyponatremia are present, patients will have clinical manifestations of weakness, drowsiness and chest tightness.