In the human vascular tissue, the carotid artery is slightly narrower compared to other arteries. However, it is responsible for transmitting blood throughout the body, and it is like the lifeline of the brain, delivering energy to the brain center at all times. Once impurities or plaque are created on the walls of the carotid artery, it will easily cause blockage, and over time, it will be like a time bomb, which may produce danger at any time, so protecting the carotid artery is protecting the health of the brain. Will there be warning signs if a plaque develops in the carotid artery? How big is a plaque considered serious? The main cause of carotid artery stenosis is atherosclerosis, which is usually aggravated by high blood pressure, high blood sugar, high blood lipids and some bad dietary habits. So, what are the general signs and symptoms of carotid artery stenosis? 1, transient cerebral ischemic attack: numbness and weakness of one limb, etc., without any signs before the onset, usually transient and reversible, usually recovering on its own after tens of minutes or hours of occurrence. 2. Cerebral ischemia: symptoms such as tinnitus, dizziness, blackout, blurred vision, dizziness, headache, insomnia, memory loss, drowsiness, and excessive dreaming. 3. Ischemic stroke, which usually manifests as sensory impairment of one limb, hemiparesis, aphasia, brain nerve damage, or coma in severe cases. Another condition may often be due to the dislodgement of carotid plaque, which enters the brain with the blood flow and blocks the distal arteries, resulting in acute cerebral infarction, which is very dangerous. All of the above signs may indicate some problems with the blood vessels. In general, if the stenosis rate of carotid artery is less than 70%, the rate of plaque proliferation can be controlled by antiplatelet drugs to prevent brain hemorrhage; if the stenosis rate is more than 50% and less than 70%, surgery can be considered. When the stenosis rate exceeds 70%, carotid endarterectomy should be performed regardless of whether there are symptoms or not. The formation of carotid plaque is generally divided into three stages from non-existent to existing. The first stage: no symptoms and mild condition, which can be treated by medication. The second stage, when symptoms appear, is the best time for treatment and can be effectively treated by carotid endarterectomy to prevent the occurrence of cerebral infarction. The third stage, the emergence of cerebral infarction, promptly take surgical treatment.