The human body has a total of four arteries supplying the brain in the neck, the carotid artery in the front and the conus artery in the back, symmetrical to the left and right, of which the carotid artery is the main supply vessel, about 80% of the blood is supplied by it. The blood flow in the blood vessels is also like the water flow in a river, following the principle of fluid dynamics. When the upper end of the carotid artery bifurcates, the blood flows from the wide artery to the narrow branch, and the flow speed will be accelerated, and the resistance at the bifurcation, the angle of the bifurcation, these three factors together cause the blood flow to form turbulence and vortex after entering the internal carotid artery leading to the brain. plaque, causing stenosis. Therefore, the internal carotid artery is the most prone to plaque formation and stenosis, and is the “window” and alarm of the cerebral vasculature as it precedes the cerebral vasculature. The human blood vessel wall has an outer membrane, a middle membrane and an inner membrane, and the three membranes are close together. Cholesterol and triglycerides in the blood do not collect on the inner membrane, but penetrate the inner membrane and collect between the inner and middle membranes, so that more and more plaques are formed and continue to thicken, then the blood vessels become narrow. The surface of the plaque is not smooth and rough, so platelets, white blood cells, red blood cells and fibrin can easily collect on it and form a thrombus. Is there a close relationship between carotid artery stenosis and “stroke”? The answer is yes, as early as 155 years ago, an American doctor, who often performed autopsies, discovered a peculiar phenomenon: all those who died of stroke, the internal carotid artery on the opposite side of the hemiplegic limb was blocked (the left side of the brain was the right limb, the right side of the brain was the left limb). This led him to think that stroke and blockage of the internal carotid artery might be related. After he published this speculation, numerous autopsies performed by other doctors later also proved that death from stroke and internal carotid artery plaque, stenosis, and blockage were indeed related. After 1968, the United States began to implement stroke screening and surgical intervention, and the mortality rate of stroke patients decreased year by year, which shows that The relationship between carotid artery stenosis and stroke is very close. Data show that 60% of strokes are due to atherosclerosis of the carotid arteries. Further studies have shown that the danger of carotid stenosis comes from two aspects: first, the stenosis itself can cause insufficient blood supply to the brain, which can lead to reduced cerebral perfusion, resulting in dizziness and discomfort, and in patients with severe stenosis, the effect of some triggers (such as agitation, falls, hypotension, etc.) can cause a sharp drop in cerebral perfusion, leading to cerebral infarction. When the stenosis caused by carotid plaque exceeds 50-60%, patients will experience a series of symptoms such as dizziness, dizziness, blurred vision, tinnitus, memory loss, arm weakness and numbness, black eyes and even transient syncope, etc. They may also experience transient disorders of consciousness, yawning caused by cerebral hypoxia, sudden inability to move their arms and legs, transient hemiplegic aphasia, etc.; secondly, unstable plaque shedding, the surface of atherosclerotic plaque is rough, like a mottled Once it falls off, it is easy to form cerebral thrombosis, which can cause a series of serious consequences such as stroke and even life-threatening. Therefore, the cause of stroke attacks seem to start in the brain, but in fact the root of the trouble is in the neck.