Clinically, there are no four reasons for tachycardia, but we should pay attention to the physiological reasons or heart problems, systemic diseases, medication factors. 1. Physiological reasons: after nervousness, anxiety or strenuous exercise, tachycardia can occur, drinking alcohol, drinking strong, strong coffee and tea due to the stimulation of sympathetic nerves, tachycardia can also occur, and generally can be recovered on their own. 2. Cardiac problems: such as myocardial ischemia, tachyarrhythmia, supraventricular tachycardia, etc., all of which can cause tachycardia, and need to be treated according to the cause. 3. Systemic problems: e.g. hyperthyroidism, fever due to various causes, anemia, etc. 4. Drugs: belladonna tablets, nifedipine tablets, etc. have the effect of accelerating the heart rate and may cause tachycardia. Since there are many causes of tachycardia, it is recommended to consult a doctor as soon as possible and take active treatment to avoid delaying the condition.