We all think about it this way: a stroke is a lesion in the blood vessels of the brain, what does it have to do with the neck? But in fact it is not. A shocking discovery of modern medicine is: brain lesions, the trouble is in the neck. Stroke (also known as stroke) is the third largest killer of human death, the type of stroke ischemic stroke and hemorrhagic stroke two types, of which ischemic stroke about 80% of all stroke patients, hemorrhagic stroke about 20%. Among the ischemic stroke patients, 10% of the patients have ischemic stroke due to the formation of thrombus in the local blood vessels in the skull, which is caused by the primary blood vessel disease that results in primary thrombosis. The remaining 90% of patients with ischemic stroke are patients with cerebral infarction due to peripheral dislodged material embolized in the intracranial blood vessels. The cause of this 90% of patients with cerebral infarction is related to the narrowing or occlusion of two carotid arteries and two vertebral arteries in the neck, and of course, the cause of the disease is also related to the dislodgement of thrombus from cardiac mucus tumors, atrial fibrillation, and other substances, which circulate with the blood to the intracranial area. However, in general, the percentage of patients with ischemic stroke due to internal carotid artery stenosis (including carotid artery and vertebral artery stenosis) is very large, which is the focus of our attention now. Why is internal carotid artery stenosis related to the development of stroke? First of all, when the narrowing of internal carotid artery reaches 70%~90%, firstly, the blood flow will be seriously blocked, so that the distal part of the brain will be damaged due to ischemia, and secondly, it will be easier to form thrombus due to the slowing down of the flow rate, which is just like the Yellow River suddenly narrowing down and slowing down the flow rate, and it is easy for the mud and sand to be precipitated and form thrombus, which will trigger the stroke; at the same time, atherosclerosis of the neck vessels that leads to the narrowing of internal carotid artery may have thrombus dislodged and be carried along with the stroke. At the same time, atherosclerosis of the neck vessels leading to narrowing of the internal carotid arteries may also cause blood clots to fall off and reach the skull with the blood circulation, resulting in the formation of cerebral thrombosis, leading to stroke.