A low heart rate of 40-50 beats per minute belongs to bradycardia. Physiological bradycardia does not require treatment, while pathological bradycardia is treated with medication, surgery, etc. Athletes, healthy young people, sleep conditions and other physiological causes can cause bradycardia. Athletes, healthy young people, sleep state and other physiological reasons can cause bradycardia, patients generally do not have obvious symptoms, most do not need treatment. Pathological bradycardia, if asymptomatic, does not require treatment for the time being, and should be regularly observed and followed up. If there are obvious symptoms related to bradycardia, such as palpitations, dizziness, darkness, loss of consciousness, etc., pacemaker implantation surgery should be carried out as soon as possible. If there is no cardiac pacing conditions, atropine, isoprenaline and other drugs can be temporarily applied in case of emergencies, but it is not suitable to be applied in the long term. Low heart rate between 40-50 beats/min should go to the hospital in time and be treated under doctor’s guidance.