Atrial fibrillation is a very common arrhythmia in our daily lives, but does it lead to sudden death after its onset? Generally speaking, atrial fibrillation does not cause sudden death, but this does not mean that atrial fibrillation is safe. Atrial fibrillation often poses the following risks: Firstly, it causes symptoms; repeated episodes of atrial fibrillation can cause symptoms such as palpitations and chest tightness in patients. Secondly, it triggers heart failure; acute episodes of atrial fibrillation are often a significant cause of heart failure, which necessitates hospital treatment for many patients. Thirdly, it leads to complications from blood clots, which is one of the most severe yet common complications of atrial fibrillation, leaving sequelae such as weakness in walking or hemiplegia on one side of the body.