Unilateral carotid artery stenosis, the current rapid economic and social development, people’s living standards continue to improve, but people’s health is gradually worrying, a variety of diseases emerge one after another, especially in recent years, cardiovascular and cerebral vascular diseases are more and more frequent. For example, in recent years, carotid artery stenosis has gradually become a more common cerebrovascular disease among middle-aged and elderly people. Carotid artery stenosis is a very dangerous disease, due to the narrowing of the carotid artery lumen, the blood flow is not smooth, the brain and facial organs of the blood supply is insufficient, can cause a lot of ischemic symptoms. For example, tinnitus, vertigo, blackout, blurred vision, dizziness, headache, insomnia, memory loss, drowsiness, dreaminess and other symptoms; vision loss, hemianopsia, diplopia, etc.; sensory disturbances in one side of the limbs, hemiparesis, aphasia, cerebral nerve damage, coma and so on. More serious cases may also cause disability, and some patients may even have life-threatening conditions. Carotid artery stenosis is also differentiated by four degrees of carotid artery stenosis. Carotid artery stenosis of less than 50% is mild stenosis, stenosis of 50%-70% is moderate stenosis, stenosis of more than 70% is severe stenosis, and if the stenosis rate reaches 100%, then the carotid artery is occluded, which is a very dangerous situation. Some patients ask what will happen if they have severe unilateral carotid artery stenosis and is it life threatening. Carotid artery stenosis is very dangerous, the lumen is already very thin, the blood flow is very small, the blood supply to the brain is seriously insufficient, and may be occluded at any time, and may cause acute cerebral infarction, which may be life-threatening. Therefore, if the carotid artery is moderately or severely stenosed, surgical treatment should be carried out in time. The ideal treatment is carotid endarterectomy. According to reports, carotid endarterectomy can completely peel out the diseased intima-media plaque, restore the size of the carotid artery lumen, restore blood flow.