Carotid artery is the main blood vessel leading from the heart to the brain. Carotid artery stenosis is mostly caused by atheromatous plaque in the carotid artery resulting in narrowing of the carotid lumen, which can gradually progress to complete occlusion. Ischemic stroke often causes disability and even death. Globally, stroke is the second leading cause of human death after ischemic heart disease and the most important factor in human disability. Foreign literature reports that 85% of strokes are ischemic, and 1/3 of ischemic strokes are caused by carotid artery disease. 1. Evidence of carotid artery disease causing stroke Prospective studies of symptomatic carotid stenosis confirm that the annual incidence of stroke in these patients is approximately 2%. Three quarters of the strokes occurred ipsilateral to the stenosis. The North American Carotid Endarterectomy Trial Group (NASCET) reported that 95% of strokes in patients treated with medication were ipsilateral to the stenosis, and the ECST also reported that 90% of ischemic strokes occurred ipsilateral to the stenosis. The beneficial effect of carotid endarterectomy in reducing stroke in patients with severe carotid stenosis (symptomatic or asymptomatic) provides further evidence for the etiology of carotid stenosis. The likelihood of stroke in patients with carotid stenosis >75% 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. 2, TIA, the prelude to stroke Paying attention to the symptoms of carotid artery stenosis is crucial to early diagnosis and treatment and to reduce the incidence of ischemic stroke. Insufficient blood supply to the brain due to carotid artery stenosis is mainly manifested by drowsiness, memory loss, and inability to concentrate at work. In severe cases, the symptoms of transient cerebral ischemia may occur: dizziness, transient black haze, loss of consciousness, and hemianopia. The onset is sudden, usually lasting only a few minutes to a few hours, and can be fully recovered within 24 hours without sequelae. The number of episodes can be as many as several times a day, or as few as once every few weeks, months or even a year or two. This transient, reversible, recurrent condition is known as transient ischemic attack (TIA), commonly known as mini-stroke. Since close to 1/3 of these patients will have a stroke within 5 years, it is often referred to as a prelude to a stroke. The stenosis caused by atheromatous plaque in the carotid artery, after microemboli dislodged from the plaque enter the brain, can cause localized microembolism in the brain causing symptoms of cerebral ischemia. The physiological compensatory reaction can in turn make the emboli dissolve, the blood vessels reopen, the cerebral blood supply is restored, and the ischemic symptoms disappear immediately, so the symptoms of transient cerebral ischemia appear in the clinic. 3, stroke prevention, surgical procedures show their skills The current treatment of carotid artery stenosis has roughly three methods: drugs, vascular stents, and carotid artery plaque stripping. Drugs are usually suitable for patients with mild symptoms, mainly oral enteric aspirin; patients with carotid artery stenosis below 70% and no obvious symptoms can be considered for vascular stenting; while patients with carotid artery stenosis above 70% and obvious symptoms are preferred for carotid endarterectomy. Compared with stenting, carotid endarterectomy is not only economical, but also has a higher safety margin. Carotid endarterectomy has long been a common procedure in Western countries to prevent stroke in patients with TIA caused by carotid stenosis and for whom surgery is indicated. In the United States, thousands of patients with TIA undergo this procedure each year to prevent stroke. Carotid endarterectomy is a common procedure in peripheral vascular surgery, in which the carotid artery is incised and the stenosed arterial segment is excised and the intima is peeled off. This procedure not only treats the symptoms of TIA but also prevents the occurrence of stroke because the stenosis of the artery is lifted and the hardened plaque is removed. Of course, there is a risk of cerebral ischemia, and not all patients with TIA require this procedure. First, imaging must be available to confirm carotid artery stenosis. The internationally accepted indications for carotid endarterectomy are mainly based on the degree of carotid artery stenosis, with a stenosis of more than 70% generally used as a criterion for mastering the surgical indications, and of course some very specific indicators, such as the presence of clinical symptoms. So far, the treatment for stroke is far from perfect. The current focus of health care is on prevention, but when the day comes, the disease itself has high mortality, disability and recurrence rates, resulting in a variety of treatment options, but the consequences are not optimistic. In terms of carotid endarterectomy, it is theoretically a near-perfect procedure, and the current surgical approach is becoming increasingly sophisticated. Carotid endarterectomy is a major step forward for mankind toward conquering stroke. There is now a new minimally invasive method, which is endovascular treatment with percutaneous transluminal angioplasty with endoprosthesis, capable of partially replacing carotid endarterectomy. elderly people over 60 years old with hypertension and coronary artery disease should visit the hospital every year for Doppler ultrasound or CT and angiography for early detection of the disease. It is more important to pay attention to the sometimes occurring blackness, sudden unconsciousness and inflexibility of the arms and legs, etc., and should go to a regular hospital immediately for appropriate examination and treatment.