The normal heart rate is 60-100 beats per minute. As long as the heart rate is within this range, it is normal even if the heart rate is slower than the next person, because the heart rate varies with age, gender, and exercise. In adults, a heart rate below 60 beats/min is called sinus bradycardia and is common in healthy young adults, athletes, and in the sleep state. However, it can also occur in a variety of pathological conditions. The corresponding hazards and treatment measures are mainly seen in the following: 1. Mild bradycardia can cause no harm. If there are no obvious symptoms, no treatment is usually necessary; 2. In more severe cases, especially when the heart rate is below 40 beats/min, fatigue, chest tightness and shortness of breath, feeling heart pain, can also lead to dizziness, weakness and black vision. If it is due to the application of cholinomimetic drugs, amiodarone, beta-receptor antagonists, calcium channel blockers or digitalis, the slow heart rate can usually be relieved after stopping the drug. If the slow heartbeat is caused by intracranial disease, severe hypoxia, hypothermia, hypothyroidism, or obstructive jaundice, the causative factors need to be promptly removed. Those with hypoxia are given a ventilated environment, those with hypothermia are moved to a warm room, and the cause of the disease needs to be treated promptly for the original disease; 3. When accompanied by hypoplastic left heart function there can be a drop in blood pressure, and in severe cases even syncope, inducing angina pectoris and heart failure, drugs such as atropine or isoproterenol can be applied for first aid. However, long-term use is prone to serious side effects, so a pacemaker should be considered for treatment.