In clinical practice, we often encounter patients who cannot feel the pulse in one hand, or the pulse in both arms is very different, and the difference in blood pressure between the two arms is found to be more than 20 mmHg, often in the left arm, and some patients experience dizziness when using one arm hard, which is a possible indication of stenosis at the opening of the subclavian artery. I. Why is the opening of the subclavian artery prone to stenosis? This is related to the principle of atherosclerosis formation. The inner wall of our arteries is covered with a layer of endothelial cells, which can prevent thrombus formation and cell retention, and the blood flow in normal vessels is laminar flow-like, which does not damage the vessel wall, but the subclavian artery originates directly from the aorta, which is just at the bifurcation, and part of the blood flow is turbulent, which has a scouring effect on the vessel wall, resulting in damage to the endothelial cells in the long run. This leads to thrombosis and atherosclerotic plaque formation. Therefore, our carotid ultrasound examination reveals a very high rate of plaque at the opening of the subclavian artery in the elderly. What are the symptoms and risks of subclavian artery stenosis? Subclavian artery stenosis is a kind of systemic atherosclerosis, just like coronary artery stenosis, but because the blood supply area of the subclavian artery is the whole arm and there is a congenital collateral circulation, the symptoms are usually not particularly serious, but mostly manifest as follows: 1. 2, blood pressure measurement, the peak systolic blood pressure difference between the two sides of more than 20mmHg. 3, “blood theft syndrome”, simply put, the normal subclavian artery needs to send a vertebral artery to intracranial blood supply, when the subclavian artery is severely narrowed, the arm blood supply can only rely on the vertebral artery to reverse the blood supply of the brain into the arm blood supply, which is called “blood theft”. This is called “blood theft”, the arm “steals blood” from the brain, so that the posterior circulation of the brain is not enough blood supply, serious cases can appear dizziness, fainting and a series of symptoms. 4. Long-term ischemia of the upper arm may lead to chronic changes such as decreased skin temperature, muscle atrophy, and muscle weakness. 5.There is also a rare case that patients with left subclavian artery stenosis, such as after bypass surgery, can lead to insufficient myocardial blood supply to the LIMA artery bridge, and the patient has severe angina symptoms, and the angina symptoms are significantly relieved after giving stent treatment. Third, how to diagnose subclavian artery stenosis? 1.Symptoms: a series of symptoms mentioned above; 2.Vascular ultrasound examination: plaque formation at the opening of the subclavian artery and accelerated blood flow in the stenosis; meanwhile, the blood flow in the vertebral artery is reversed or in both directions; 3.Vascular enhancement CT: it can diagnose the degree and location of stenosis in the subclavian artery; 4.Angiography: it can confirm the degree and location of stenosis and give interventional treatment at the same time. IV. How to treat? 1.Medication: Anti-atherosclerosis treatment, the same as the medication for coronary heart disease. 2.Interventional treatment: Interventional stenting is the most effective treatment for severe stenosis of the subclavian artery, because the diameter of the subclavian artery is significantly wider than that of the coronary artery, and the diameter of the stent is basically about 6-10mm, so the recovery after surgery is fast and the effect is immediate. Subclavian artery stenosis is a not uncommon disease, which is still under-recognized clinically, and interventional stenting is effective.