Statistics show that the top three causes of death in the elderly are cardiovascular diseases (70%), tumors (15%), and respiratory diseases (12%). In China, cerebrovascular disease (stroke) is more common than coronary heart disease, accounting for the first or second cause of death among the elderly, with the “three high” characteristics of high incidence, high disability rate and high mortality rate, and is a common disease that threatens the health of human beings, especially the middle-aged and elderly. Stroke can be divided into two types: hemorrhagic and ischemic. The latter is more common than the former, with a ratio of 4:1. Blood to the brain is supplied by four vessels outside the skull: the left and right carotid arteries and the vertebral artery. A lesion in any one of them can lead to cerebral ischemia and cause stroke. Among them, carotid stenosis is the most common, accounting for about 80% of extracranial and intracranial occlusive lesions. How does carotid artery stenosis cause stroke? As the body ages and the blood vessels harden, atherosclerotic plaques can form in the arteries, causing carotid artery stenosis. These plaques increase in size and gradually become calcified, hemorrhagic, necrotic and can attach to the surface to generate thrombus, which leads to debris and thrombus on the surface of the plaque and flow to the distal intracranial vessels to form an embolism. After the debris is dislodged, pro-thrombogenic substances such as collagen are exposed within the plaque, leading to new thrombus formation and continued dislodgement leading to repeated embolization of the distal vessels. Stenosis of the carotid artery itself can also cause hypoperfusion of blood flow to distal brain tissue. Data suggest that ischemic stroke (stroke) is caused by carotid artery stenosis in about 80% of cases. The incidence of stroke within 2 years can be as high as 26% in more than 70% of patients with symptomatic carotid stenosis. However, due to the influence of some traditional concepts in the domestic medical community, from physicians to patients, there is a lack of proper understanding of the relationship between the treatment of carotid stenosis and stroke, and they tend to pay attention to the treatment after stroke but not to the prevention of stroke (especially the examination of carotid stenosis), and to the treatment of brain cell function recovery after stroke but not to the treatment of carotid plaque. Therefore, it is of great practical significance to pay attention to carotid stenosis. Our vascular surgery department has rich experience in the diagnosis and treatment of carotid artery stenosis, and in the subsequent series of articles, we will systematically introduce the knowledge about the etiology, diagnosis and treatment of carotid artery stenosis. We hope that through our efforts, we can serve the health of elderly patients.