The severity of sinus tachycardia depends on the cause; physiologic tachycardia is not serious, and pathologic tachycardia is dangerous. Normal adult heart rate is 60~100 beats/min, sinus tachycardia is the frequency of adult sinus rhythm over 100 beats/min. 1. Physiological sinus tachycardia: It is common in healthy people, smoking, drinking tea or coffee, drinking alcohol, physical activity and emotional excitement, and can be relieved on its own, which is a physiological phenomenon and not serious. 2. Pathological sinus tachycardia: fever, hyperthyroidism, anemia and other diseases, the application of adrenaline or atropine and other drugs can lead to sinus tachycardia, according to the doctor’s instructions to timely treatment of the primary disease, adjusting the relevant medication to the stabilization of the condition. Timely medical regulation can be, is not serious. If delayed treatment leads to complications, it will be more serious. In addition to the above causes, acute heart failure can also lead to sinus tachycardia, often manifested as dyspnea, profuse sweating, or even shock to death. These cases are very serious and should be treated promptly. If a patient experiences any of the above symptoms, he or she should go to the hospital immediately to avoid delaying the condition.