The carotid artery is the main channel for supplying fresh blood from the heart to the brain, and its health is not to be compromised, because it is a lifeline channel. Once the carotid artery has problems and the blood supply to the brain becomes abnormal, it will have a significant impact on the operation of the whole body. When atherosclerosis occurs in the carotid artery, it will lead to the formation of atheromatous plaque, and the growing plaque will make the carotid artery channel become narrow. In clinical practice, carotid artery stenosis can be mild or severe. A stenosis of 50% or less is considered mild carotid artery stenosis, while if the stenosis exceeds 70%, it is already severe carotid artery stenosis. What should I do if I have severe stenosis of the left carotid artery? There is one carotid artery on the left and one on the right. When the left carotid artery has severe stenosis, we should also pay attention to the condition of the right carotid channel and take timely measures to treat it. For mild carotid artery stenosis, conservative medication is usually used to control the growth of plaque, but for severe carotid artery stenosis, medication alone is not very meaningful and surgical treatment is needed to achieve better results.