A low heart rate of 40 beats per minute is usually related to physiological factors, hypothyroidism and sinus bradycardia, and can be treated with general therapy or medication according to the cause. 1. Physiological factors: such as emotional depression, physical fatigue, poor mental state, etc., may lead to low heart rate, which is a normal psychological manifestation and requires no special treatment and regular observation. 2. Hypothyroidism: clinically known as hypothyroidism, when the thyroid hormone is insufficient, low heart rate will occur. The treatment of this disease requires timely supplementation of levothyroxine tablets, if the heart rate continues to fall, oxygen therapy may be needed, and ensure that the body has enough oxygen; also need to pay attention to warmth, to avoid the body from getting cold so that the heart rate falls rapidly. 3. Sinus bradycardia: It is a kind of sinus rhythm, which mainly refers to the number of heartbeats less than 60 times/minute. For mild bradycardia, you can choose to take atropine, ephedrine to enhance the heart rate; if the condition is serious, a pacemaker should be installed in time. Low heart rate, need to clarify the cause before targeted treatment. Before treatment, it is necessary to go to the hospital for examination, and then combined with the doctor’s advice to choose the best treatment plan, if you need to use medication, should be strictly in accordance with the requirements of the doctor.