The common causes of sudden death in pulmonary edema are severe respiratory failure, or cardiac arrest due to hypoxia and other factors. 1. Severe respiratory failure: when pulmonary edema occurs, due to the increase of fluid in the alveoli and the increase of fluid content in the interstitial fluid, it affects the ventilation-exchange function, leading to hypoxia, respiratory failure and other complications, and when the respiratory failure is severe, it may lead to the occurrence of sudden death. 2. Cardiac arrest caused by hypoxia or other factors: severe hypoxia may have an effect on the heart, which may cause malignant arrhythmia and cardiac arrest. In addition, sometimes pulmonary edema is caused by cardiac diseases, such as cardiac diseases, cardiac arrest may also occur, and the above cases can also cause sudden death. Therefore, patients with pulmonary edema need to be actively treated for hypoxia and its causes, as well as for cardiac disease to prevent sudden cardiac arrest.