Carotid artery is the main source of blood supply to the brain, and carotid artery stenosis or occlusion is the main cause of “stroke”. As people age, and under the influence of a series of factors such as smoking, hypertension, hyperlipidemia, reduced exercise, and emotional stress, blood vessels are aging, resulting in the formation of a “scale” like flab in the lumen of the blood vessels that adheres to the walls of the vessels (what we usually call atherosclerosis), blocking the passage of blood flow. This causes narrowing of the blood vessels. Carotid artery stenosis occurs when “scale” is present on the carotid artery. When the carotid artery has different degrees of narrowing, the brain also has different degrees of ischemia. The main symptoms are tinnitus, blurred vision, headache, dizziness, memory loss, fatigue, drowsiness, insomnia, and excessive dreaming. In severe cases, repeated syncope, even hemiplegia, aphasia and coma can occur. A few people can have vision loss, partial blindness, diplopia, or even sudden blindness. The most serious consequence is the detachment of atherosclerotic plaque and blockage of the intracranial carotid artery, causing cerebral infarction (stroke), hemiplegia, incontinence, inability to take care of oneself, and even loss of life. There are three types of treatment for carotid artery stenosis: medication, carotid endarterectomy and carotid stentoplasty. 1.Drug treatment. The basic method is to take antiplatelet drugs for a long time, and further treatment is generally recommended for patients with more than 75% stenosis. 2.Carotid endarterectomy. The basic method is endarterectomy to release arterial stenosis and atherosclerotic plaque, restore blood supply to the brain and eliminate the source of cerebral infarction emboli. This procedure is relatively mature and has been carried out for more than 50 years. 3. Carotid artery stentoplasty. This is a method of applying balloon dilation and then placing a stent in the narrowed carotid artery under a brain protection device. When is treatment needed? Surgery or stenting is required when: 1. The degree of carotid stenosis exceeds 75%; 2. The degree of carotid stenosis is less than 75%, but the symptoms of cerebral ischemia such as dizziness and blackness are typical, or the sclerotic plaque is unstable and easily dislodged; 3. Medication is not effective, there is a history of stroke attack, or there is still a minor stroke attack after cerebral infarction.