What is occlusive arterial disease of the lower extremities? The definition of arterial occlusive disease of the lower extremities should have a broad and narrow distinction. In the broad sense, occlusive arterial disease of the lower extremity refers to acute or chronic occlusion of the arteries of the lower extremity due to various causes, such as atherosclerosis, arteritis, arterial embolism, arterial trauma, and anatomy. The narrow definition of lower extremity arterial occlusive disease refers to arterial stenosis or occlusive disease due to atherosclerotic plaque, which mostly develops chronically, although there are patients who experience acute exacerbation based on chronic development. The narrow definition is more widely used, as this condition accounts for approximately 90% or more of all occlusive arterial disease in the broad sense. What are the symptoms of arterial occlusive disease of the lower extremities? Early stage arterial occlusive disease of the lower extremities may not have definite symptoms and may occasionally have symptoms such as slightly low skin temperature in the distal extremities of the lower extremities or cramping after exposure to cold. A more definite early symptom would be impairment of walking function, or what doctors call intermittent claudication. By intermittent claudication, we mean that when a patient walks for a period of time, discomfort or pain in the lower extremity occurs, which is relieved soon after rest. The symptoms of this claudication can be not pain, but also weakness, soreness, heaviness and other manifestations, and the parts where the symptoms appear can be in the buttocks, thighs, calves and toes, with the calves being the most common. Symptoms appear more quickly when walking quickly or going upstairs. As time passes and the condition worsens, the distance over which symptoms appear becomes shorter. Overall, however, only 50% of patients with lower extremity ischemia will have symptoms of intermittent claudication; in other words, the absence of symptoms of intermittent claudication is not the same as not developing arterial occlusive disease of the lower extremities. The main reason for intermittent claudication is that the oxygen and nutrient requirements of the tissues of the lower extremities increase exponentially when walking, and the occluded arteries are unable to meet this increased demand. If the degree of arterial occlusion in the lower extremity worsens further, the patient may develop severe lower extremity ischemia. The blood supply in the arteries of the lower extremity is no longer sufficient to meet the needs of the limb at rest, resulting in ischemic pain in the lower extremity at rest, or what physicians call resting pain. This pain is characterized by even more reduced blood flow due to the relative elevation of the lower extremity when lying down, resulting in more painful symptoms during sleep. If the condition continues to worsen, breakouts and ulcers may develop in the toes or ankles and are very painful. If the ischemic condition does not improve in time, the ulcer will gradually worsen, gradually changing from dry, grayish white at the beginning to black and eventually developing into necrotic tissue (gangrene). What risk factors can cause lower extremity arterial occlusion Atherosclerosis is the root cause of lower extremity arterial occlusion. All factors that can lead to the occurrence and development of atherosclerosis may be risk factors for lower extremity arterial occlusion. 1, Age: The incidence of arterial occlusion increases significantly with age. In people before the age of 50, relatively few patients develop Peripheral Arterial Disease (PAD), while in people over the age of 70, the incidence of PAD can reach 10-20%. 2. Diabetes: All diabetic patients older than 50 years of age should routinely undergo regular lower extremity arterial examinations, and about 1/3 of these patients will be at risk for lower extremity arterial occlusion. And relative to those without diabetes, this group of patients has earlier onset of symptoms, more severe symptoms, and a higher rate of eventual amputation. This is because patients with diabetes have simultaneous damage to their peripheral nerves and a greatly reduced ability to protect themselves. Once found to have diabetes, it is very meaningful to maintain a stable blood sugar level. 3. hypertension 4. hyperlipidemia 5. hyperhomocysteinemia 6. previous cardiovascular or cerebrovascular events 7. overweight, especially those over 30% of normal body weight Why does arterial occlusion of the lower extremities cause ischemic symptoms The aorta is the largest artery in the body and the main artery that carries arterial blood rich in oxygen and nutrients to the extremities and various organs, ensuring that these organs metabolism. The abdominal aorta divides into the right and left iliac arteries at about the level of the umbilicus in the abdomen and supplies blood to the lower extremities bilaterally. When the arteries of the lower extremities become narrowed or occluded, the blood flow to the buttocks, thighs, calves, or toes will be inadequate, and the exact site and severity of ischemia will vary depending on the location and degree of occlusion and the compensation of the collateral circulation. However, the lower extremities will always be unable to perform normal activities due to insufficient blood flow, and in severe cases, symptoms of ischemia may occur even without activity. Why does atherosclerosis cause arterial occlusion? Normal artery walls are smooth and the lumen is continuous without blockage. However, due to ageing, the walls of human arteries gradually develop a kind of lipid deposits and gradually evolve into atherosclerotic plaques. Plaque is generally composed of cholesterol, calcium and fibrous tissue, and is mostly located at the bifurcation of arteries. If the plaque continues to grow, it causes the lumen of the artery to narrow and eventually occlude, which may be a chronic process. However, there are times when the fibrous cap of the atherosclerotic plaque can spontaneously rupture, leading to an acute thrombotic event in the artery, resulting in an acute exacerbation of arterial ischemia.