Once atrial fibrillation occurs, it will bring some harm and not to the body, specifically: ① Thrombosis and embolism: Atrial fibrillation when the atria lose contraction function, blood is easy to stagnate in the atria and form thrombus, thrombus can be dislodged with the blood to all parts of the body, leading to brain embolism (stroke, hemiplegia), limb artery embolism (serious cases even require amputation), etc.. The annual incidence of stroke is about 1% in patients with atrial fibrillation who are younger than 60 years old without other diseases, and 2% in patients who are 60-75 years old or older. In the presence of other embolic risk factors, the annual incidence of stroke can be up to 4%. Risk factors for stroke in patients with atrial fibrillation include a history of previous embolism, hypertension, diabetes, coronary artery disease, heart failure, left atrial enlargement, and age over 65 years. (ii) Rapid heart rate and irregular rhythm may cause palpitations in patients. ③ Loss of atrial systolic function and prolonged increase in heart rate can lead to heart failure. ④ Increased mortality (twice as high as normal). Patients with atrial fibrillation should be seen promptly and treated aggressively to prevent thromboembolism and heart failure.