Left anterior branch block in young people is usually fine, but the presence of left anterior branch block in the presence of underlying heart disease, such as coronary artery disease, suggests that the condition may be aggravated. Left anterior branch block is a common type of electrocardiogram, which refers to the left anterior branch of the heart’s conduction system in which conduction is blocked, and is an abnormal manifestation. In young people, if there is no underlying cardiac disease, it is usually not serious; however, if it is accompanied by underlying cardiac diseases such as coronary artery disease, myocardial ischemia, myocardial infarction, etc., the presence of left anterior branch block indicates that the condition may be aggravated. Therefore, when left anterior branch block occurs, it is recommended to consult a cardiologist or cardiac surgeon and improve the relevant examinations under the guidance of the doctor to exclude cardiac function and organic lesions, so as not to delay the diagnosis and treatment of the condition.