The causes of bradycardia include physiologic, primary causes, secondary causes, etc., and the treatments are medications, pacemaker therapy, etc. 1. Causes. Physiological: some fitness enthusiasts, athletes, etc., due to strong heart reserve function, the heart rate is often lower than 60 beats per minute, or at night when resting, the heart rate will be reduced. Primary: including sinus node dysfunction, atrioventricular block and other causes, belonging to the heart caused by primary diseases, such as sick sinus node syndrome, acute inferior wall myocardial infarction. Secondary: It is caused by other systemic diseases, including intracranial diseases, hypothyroidism, etc., or due to hypothermia and drug effects. 2.Treatment. Physiologic causes usually require no treatment. Drugs: For primary causes, drugs can be used to elevate the heart rate, such as atropine and isoproterenol, etc. For secondary causes, the treatment is directed at the primary disease, such as taking eugenol to treat hypothyroidism and elevate the body temperature. Pacemaker therapy: For sinus node dysfunction when drugs are ineffective, pacemaker therapy can be used. When bradycardia occurs, it is important to consult a doctor in time to find out the cause and then further treatment according to the situation, so as not to delay the condition.