The relationship between carotid stenotic lesions and cerebral ischemic stroke is very close. Stroke caused by carotid stenosis includes the following: i) direct reduction of cerebral perfusion due to severe stenosis; ii) dislodgement of carotid atheromatous plaque or dislodgement of microthrombus formed by plaque rupture. Clinically, there are three main types of stroke, 1, subclinical stroke; 2, transient ischemic attack (TIA); and 3, symptomatic stroke. Studies have shown that nearly 1/3 of strokes occur in association with obstructive lesions in the extracranial carotid arteries, especially carotid stenosis from 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. After it was recognized that one of the important causes of ischemic stroke is carotid plaque and carotid artery stenosis, people began to focus on screening and early intervention for this disease. Currently, a mobile stroke screening network has been established in the United States. In recent years, experts in China have found that many patients with stroke signs due to carotid stenosis, such as impaired limb movement, aphasia, hearing loss or even loss, retinal or macular degeneration, and significant vision loss, have significantly improved or recovered after carotid stenosis is lifted. By screening the condition of carotid arteries, it is possible to give early behavioral guidance or pharmacological interventions to patients with less severe stenosis to slow down their stenosis progression, and to provide interventional or surgical treatment to patients with severe stenosis to remove the source of their strokes and reduce their occurrence. Carotid screening is a relatively simple, non-invasive and inexpensive test. Patients with severe stenosis can be detected by neck auscultation; using neck ultrasound, the vast majority of patients with stenosis can be detected and their degree of stenosis determined. Further investigations can be performed with CT angiography, MRI, or direct angiography in order to clarify the degree and extent of stenosis, as well as to discriminate the nature of the plaque, detect unstable plaque early, and treat it promptly to prevent more serious vascular events or strokes. The main risk factors for carotid stenosis are: hypertension, hyperlipidemia, hyperglycemia, long-term smoking history, long-term heavy alcohol consumption, etc. In the past, severe carotid stenosis was almost always over the age of 60, 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 and at risk of stroke lowering sugar, lipids and blood pressure is an important preventive measure; at the same time, it is important 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 performed. Carotid artery stenosis treatment: generally divided into drug treatment, interventional treatment, and surgical treatment. Surgical treatment: The main treatment is 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 procedure has been performed for many years and is relatively mature. The advantage of this procedure is that the chances of restenosis occurring after surgery are low, and generally less than 10% of restenosis occurs within one year. Surgical treatment of carotid stenosis: Patients with carotid stenosis >75%; or patients with carotid ulcerated plaque need to undergo surgical treatment. Drug therapy: mainly antiplatelet therapy. Interventional treatment: mainly carotid stenting PTA carotid stenting. The chances of recurrent stenosis after carotid artery stenosis surgery are not very high, and only pharmacological treatment is usually available.