Sinus bradycardia is a condition in which the adult’s sinus rhythm is less than 60 beats per minute. The causes of sinus bradycardia are many, including physiological and pathological two kinds, the former mostly occurs in healthy young people or athletes and sleep state, is a normal physiological signs; the latter may be due to heart disease, drug factors, electrolyte disorders, metabolism lowering, sleep respiratory syndrome and other causes. Sinus bradycardia caused by physiological factors usually has no obvious symptoms, while sinus bradycardia caused by pathological factors has different manifestations depending on the severity of the disease. Usually, when the sinus rhythm is at 40-60 beats per minute, the patient may be asymptomatic or only have chest tightness and other discomforts; if the heart rate is lower than 40 beats per minute, symptoms such as fatigue and dizziness may occur. If the patient has sinus bradycardia along with other more serious heart conditions, he or she may exhibit precordial pain, dizziness, and fainting. Most pathological causes of sinus bradycardia are often accompanied by symptoms such as arrhythmia. Sinus bradycardia triggered by physiological factors usually does not require special treatment, while sinus bradycardia triggered by pathological factors needs to alleviate the symptoms by treating the primary cause of the disease, which can usually be treated with medication and surgery. A heart rate of 40 beats or more at rest usually does not cause obvious symptoms, but a heart rate that remains slow and cannot be effectively raised in an active state will have corresponding symptoms and dangers, and requires prompt treatment. If a patient has sinus bradycardia, he or she should go to the hospital in time for examination to clarify the cause. If it is caused by pathological reasons for this type of condition, early targeted treatment should be carried out.