The causes of sinus bradycardia are physiologic and pathologic, physiologic such as during sleep, normal people may occur during sleep sinus bradycardia, and then there are athletes, because under the premise of sports and exercise, the heart compensatory capacity is relatively strong, sinus bradycardia also occurs, but this is not a heart disease. If sinus bradycardia occurs under pathological conditions, it may be a kind of heart disease, such as coronary artery disease, myocardial infarction, cardiomyopathy, etc., which may lead to sinus bradycardia, so sinus bradycardia in this case needs to be taken seriously, and it may be a kind of indicator that the patient may suffer from fatigue and chest tightness because of the bradycardia. If if the heart rate is too slow, there may be some risk of it happening at any time. So this condition needs to be differentiated to see under what conditions sinus bradycardia occurs and can be identified again.