Heart rate of 55 beats per minute for a long time is bradycardia, abnormal, normal heart rate is 60 to 100 beats per minute. Causes of bradycardia have physiological factors and pathological factors, patients with bradycardia, should consult a doctor in time for diagnosis, and follow the doctor’s instructions for relevant treatment. 1. Physiological factors: long-term exercise, sleep at night, in the environment is too hot and other factors can cause bradycardia, general patients do not need special treatment, appropriate changes in lifestyle. 2. Pathological factors: non-cardiovascular system diseases such as hypothyroidism, hyperkalemia, cardiovascular system diseases such as myocardial ischemia, myocarditis, etc. can cause bradycardia, patients can consult a doctor in a timely manner to find out the cause of the disease, and specific treatment. Bradycardia patients, must actively cooperate with the physician for treatment, not blindly use their own medicine, so as not to aggravate the condition, delay treatment.