The carotid artery is the main blood vessel that carries blood from the heart to the brain and other parts of the head. Carotid artery stenosis is mostly due to narrowing of the carotid lumen caused by atheromatous plaque in the carotid artery, and some stenotic lesions may even progress to complete occlusive lesions. The relationship between carotid stenosis and cerebral ischemic stroke is very close. I. Stroke caused by carotid stenosis Clinically, there are three main types: subclinical stroke; transient ischemic attack3, and symptomatic stroke. Nearly 1/3 of strokes are associated with obstructive lesions of the extracranial carotid arteries, especially carotid stenosis due to various causes. The literature shows that in patients with carotid stenosis >75%, the likelihood of stroke is 10.5% within 1 year and 30%-75% within 5 years; in patients with carotid stenosis of 70%-90% and combined with cerebral ischemia, 26%-28% will have a stroke within 1 year. This shows that carotid stenosis and cerebral infarction are closely related. The method of carotid artery screening is relatively simple, non-invasive and inexpensive. Patients with severe stenosis can be detected by neck auscultation; using neck ultrasound, the majority of patients with stenosis can be detected and the degree of stenosis can be determined. Further examinations can be performed with CT angiography, MRI, or direct angiography in order to clarify the degree and extent of stenosis, and also to discriminate the nature of the plaque, detect unstable plaque early, and treat it in time to prevent more serious vascular events or strokes. Third, the main risk factors of carotid stenosis hypertension, hyperlipidemia, hyperglycemia, long-term smoking history, long-term heavy alcohol consumption, etc. In the past, severe carotid stenosis was almost always over 60 years old, but recently there are more and more patients in their 40s and even younger. It is generally believed that the rejuvenation of carotid stenosis is related to hypertension, diabetes, and the rejuvenation of atherosclerosis, and is closely related to emotions, life and work stress. Therefore, people over 45 years old with two of these risk factors should undergo carotid screening. From the above risk factors for carotid stenosis, there are the same risk factors as stroke score, which in turn indicates the close relationship between carotid stenosis and cerebral infarction. These risk factors include: hypertension, diabetes, dyslipidemia; risk factors also include: smoking, alcohol abuse, obesity, and age. For patients with carotid artery sclerosis or stenosis or even occlusion, lowering sugar, lipids and blood pressure is an important preventive measure; at the same time, it is necessary to treat the primary disease, control risk factors such as obesity, alcoholism and smoking, and at the same time dilute blood to prevent thrombosis – antiplatelet therapy is carried out. Fourth, carotid artery stenosis treatment is generally divided into drug treatment, interventional treatment, and surgical treatment. 1.Surgical treatment: mainly carotid endarterectomy (CEA), carotid endarterectomy is to restore blood supply to the brain and eliminate the source of emboli in cerebral infarction by removing the thickened carotid endarterectomy atherosclerotic plaque. The operation has been carried out for many years and is relatively mature. The advantages of this operation are: the chance of re-stenosis after the operation is not high, generally less than 10% of re-stenosis occurs within one year. 2.Pharmaceutical treatment: mainly antiplatelet therapy. 3.Interventional treatment: mainly carotid stenting PTA carotid stenting. The chance of recurrent stenosis after carotid artery stenosis surgery is not too high, and generally only pharmacological treatment can be used.