Arterial embolism is a pathological process in which an embolus is dislodged from the wall of the heart or proximal artery, or enters the artery from outside and is pushed distally by the blood flow, blocking the arterial blood flow and causing ischemia or necrosis of the limb or internal organs. In peripheral arterial embolism, the affected limb shows pain, pallor, loss of distal arterial pulsation, syncope, numbness and dyskinesia. Qualitative diagnosis of patients with sudden onset of severe limb ischemic signs and disappearance of corresponding arterial pulsations, i.e., those with 5P sign, with organic heart disease, atherosclerosis, especially with atrial fibrillation, recent myocardial infarction or abdominal aortic aneurysm, can be clearly diagnosed. Localization to diagnose the location of embolic obstruction can be made by: 1. the location of the initial pain 2, the plane of disappearance of normal pulse, the plane of alteration of skin temperature and skin color, etc. 3, non-invasive examination (such as Doppler ultrasound, etc.). 4.The extent of circulatory disturbance in the limb. 5.The embolus is easy to stay at the arterial bifurcation and other characteristics to determine.