I. What exactly is carotid plaque? As blood flows continuously in the blood vessels all year round, the lipid components in the blood will be slowly deposited on the vessel wall, gradually forming plaque, which is related to age and smoothness of the vessel lining. Classical plaque development can be divided into four periods: 1. lipid pattern stage As the name suggests, the lipid pattern can be seen on the vessel wall; 2. fibrous plaque stage At this time, there are less lipid components in the plaque, and the fibrous material is mainly; 3. atheromatous plaque stage There are soft lipid materials in the plaque, and the plaque looks grayish-yellow, but because the surface of the atheromatous plaque is still covered with a layer of fibrous material As a protection, so it will not cause any effect to the body yet; 4. Secondary lesion stage of plaque The fibrous-like material on the surface of plaque will be broken, the local of plaque may induce thrombosis, and the lipid material may also be shed to the distal end of blood vessel, this is the stage that plaque will cause harm. When we perform carotid ultrasound to find plaque formation in carotid vessels, it will be mainly in the fibrous plaque stage, and a few will be in the atheromatous plaque stage, so there is no need to be blindly nervous. In the United States, 62% of people older than 40 years old who underwent ultrasound examination had carotid plaque. In Japan, carotid ultrasound examination of healthy people aged 46-74 years showed that 75.1% of them had carotid plaque. In China, the detection rate of carotid artery plaque was 60.3% when carotid ultrasonography was performed on middle-aged and elderly people. From the above statistics, we can see that the detection rate of carotid plaque in any country is more than 50%, which means that carotid plaque is a disease that most people will suffer from. There are two types of carotid plaque: 1. one is just a manifestation of the aging process; 2. the other carotid plaque will lead to narrowing of blood vessels and lead to cerebral blood supply deficiency or cerebral infarction. Second, will carotid plaque lead to brain infarction There is no doubt that the occurrence of carotid plaque is significantly correlated with cardiovascular and cerebrovascular events, however, only those unstable plaques, also called high-risk plaques, are associated with stroke, and most people’s carotid plaques are of the stable and safe type. Some carotid plaques can lead to cerebral infarction in two ways, the first being that the carotid plaque grows large enough to cause severe stenosis of the internal carotid artery, causing inadequate blood supply to the distal brain tissue. When we look at the ultrasound report, we will see an indicator of the thickness of the carotid plaque. Since the diameter of the internal carotid artery is 5-6 mm, the thickness of the plaque will not significantly affect the blood supply to the brain tissue as long as it is less than 4 mm. A simpler way is to look at the flow velocity in the ultrasound report: normal carotid flow velocity is less than 100 cm/sec. If the flow velocity exceeds 200 cm/sec, it means that the carotid artery is stenosed and needs to be treated with the help of a specialist. As for the principle of stenosis leading to faster flow rate, it is the same as when we use our fingers to block the tap to cause a significant increase in water flow rate. The second way in which carotid plaque leads to infarction is that the fibrous material on the surface of the unstable plaque is incomplete, and the lipid-like material comes into direct contact with the blood. On the one hand, the lipid-like material will induce thrombosis, and on the other hand, the lipid-like material itself will be dislodged, causing blockage of the distal cerebral vessels. Therefore, as long as the carotid ultrasound results do not reveal any increase in blood flow velocity and there is no unstable plaque, regardless of whether the plaque echo is strong, weak or inhomogeneous, it is safe and there is no need to worry about the occurrence of cerebral infarction. Of course, it would be more reliable if the report can be taken to a professional doctor for interpretation. Thirdly, whether plaque needs to take medicine or not We should emphasize that the risk factors that cause plaque include high blood pressure, high blood sugar, smoking and alcohol consumption, all of which will lead to endothelial damage, making it easier for lipid substances to be deposited on the blood vessel wall, thus inducing plaque volume to increase. Therefore, blood pressure and blood sugar should be controlled within normal range by medication after plaque discovery, and it is also necessary to quit smoking and alcohol as well as to keep a good state of mind. The main component of plaque is lipid, so reducing the lipid content in blood is to control the source of plaque, which is theoretically meaningful to prevent the increase of plaque volume, but considering the side effects of lipid-lowering drugs, it is not necessary to take lipid-lowering drugs when plaque is found. At present, the unified opinion at home and abroad is that if the degree of stenosis caused by carotid plaque is less than 50% and the blood lipid is within the normal range, it is possible not to take lipid-lowering drugs, but to take drugs if the blood lipid is abnormal. If the degree of stenosis caused by carotid plaque is greater than 50%, medication should be taken regardless of whether the blood lipids are abnormal or not. Therefore, for those who are found to have no symptoms during physical examination and are further evaluated as stable low-risk carotid plaque, if they do not have high blood lipids, it is more appropriate to control carotid plaque by changing diet and increasing exercise without taking lipid-lowering drugs first. How to review carotid plaque Many outpatients are very nervous once carotid plaque is found, and they come to the hospital every 2-3 months to review ultrasound to see if there is any change in plaque. Sometimes slight changes in plaque thickness due to errors of ultrasound examiners and instruments can cause a lot of psychological stress to patients. In fact, many studies have shown that the annual growth of carotid plaque is generally not more than 1mm, so it is enough to check carotid plaque once a year during physical examination, and there is no need to check carotid ultrasound repeatedly within a short period of time. The energy saved should be spent on controlling blood pressure, blood glucose, blood lipids and other indicators, and reducing the risk factors for plaque growth is the most important thing to do. Of course, this refers to plaque thickness less than 4mm, plaque that does not cause significant stenosis, and stable low-risk plaque, otherwise, it is better to ask professional doctors to assist in the evaluation of the specific review method. In conclusion, carotid plaque is actually a window to the degree of atherosclerosis in the human body, and we need to pay attention to plaque changes to assess the risk of cerebrovascular disease.