Intraluminal sinus tract compression of the arterial lumen due to intimal separation may be associated with distal arterial embolic obstruction. However, these patients often have chest and back pain, a long history of hypertension, an auscultatory murmur, and a widened mediastinum on chest radiographs, which can help in the diagnosis. Where sudden onset of limb pain with acute arterial ischemic manifestation and disappearance of corresponding arterial pulsation, the diagnosis is generally established. Acute arterial embolism without collateral circulation compensation will result in acute limb ischemic signs: Pulselessness, Pain, Pallor, Paresthesia and Paralysis, i.e. 5P signs. The appearance of the above phenomena and their degree are related to the degree of ischemia. 1. Weakness or loss of arterial pulsation: It occurs in the distal arteries of the embolized arterial segment. Sometimes, due to the impact of blood flow, a conductive pulsation may be palpable in the artery distal to the embolization. If the embolization is incomplete, a weakened distal arterial pulsation may be palpable. In addition, arterial embolization will cause pressure pain in the affected artery, which usually occurs proximal to the ischemic changes in the limb. Using ultrasound Doppler stethoscope or blood flow recorder, normal arterial sounds cannot be heard or no arterial waveform appears, which is a more reliable examination method. 2. Pain: After arterial embolism, most patients have severe pain in the limb that occurs sharply. The pain starts at the embolization site, and then gradually extends to the distal limb of embolization. The pain site can be displaced, when the dislodged embolus rides across the bifurcation of abdominal aorta, it is manifested as severe abdominal pain; if the embolus is washed to the femoral artery by blood flow, it is transformed into femoral pain. The affected limb has tenderness, and active or passive activities of the limb can cause pain, thus being in a braking state. 3. Pallor and decreased skin temperature: The skin is waxy and pale due to impaired blood supply to the distal part of the embolized artery. If there is still a small amount of blood in the subcutaneous venous plexus, there are cyanotic spots of different sizes on the pale skin base. The superficial veins are deflated due to reduced blood flow. Skin temperature changes are related to the site of arterial embolism. When the bifurcated segment of the abdominal aorta is embolized, the skin temperature of the buttocks and bilateral lower extremities decreases; when the iliac artery is embolized, the skin temperature of the ipsilateral thigh decreases, while in the case of common femoral artery embolism, the skin temperature decreases below the middle of the thigh, and in the case of arterial embolism, the skin temperature of the middle calf and its distal side decreases. In embolism of the subclavian and axillary arteries, the symptoms involve the entire upper extremity; in embolism of the brachial artery, the symptoms involve the forearm; in embolism of a single branch of the ulnar radial artery or the anterior and posterior tibial arteries, the symptoms are limited and milder because of the abundant collateral circulation. Skin temperature changes can be detected by the following methods: ①The examiner touches the affected limb with the dorsal side of the middle finger of the middle index finger and moves it from the proximal to the distal side, and can detect the plane where the skin temperature of the affected limb decreases. ②Compare the skin temperature of the same plane of both limbs by the same method, and the skin temperature of the affected limb can be detected to be lower than that of the non-embolized limb. ③Using the skin thermometer to compare and measure the bilateral limbs, the degree and plane of skin temperature reduction can be measured. 4.Sensory and motor disorders: When peripheral nerve has ischemic damage, the distal end of the limb can have skin sensory loss area, and its proximal end has sensory loss area and skin sensory sensitive area. When the embolism is long, there is already ischemic necrosis of peripheral nerve damage and muscle tissue, it can cause finger and toe movement disorder, hand and foot drooping and other symptoms. The examiner can detect the skin sensory disorder of the affected limb by touching the skin of the affected limb with the hand or by the simple method of needling. Passive movement of the fingers or toes of the affected limb can clarify the presence or absence of deep sensory loss. 5.Tissue necrosis: Once the arterial embolism has a long course, irreversible tissue ischemic necrosis will occur eventually. In addition to the dry necrosis of fingers or toes caused by terminal artery embolism, when the main artery is blocked, the tissue necrosis is widespread, with cold limb, dark purple color and reticular cyanosis; skin blisters, containing bloody exudate; tissue thickening and hardening. At this time, there are obvious systemic symptoms: depression, high fever, chills, accelerated heart rate, and even lower blood pressure and other toxic symptoms.