Carotid artery plaque is divided into two types of conditions: mild cases usually do not cause dizziness, while severe cases may cause dizziness, and more serious cases may lead to cerebrovascular blockage, cerebral infarction, hemiplegia, or even affect life. Carotid atherosclerosis is related to lifestyle habits, such as staying up late, drinking a lot of alcohol, smoking, and also related to age. When the blood vessels are mildly stenosed, they do not cause changes in hemodynamics and generally do not cause dizziness. In severe stenosis, dizziness can occur, especially in the posterior circulation, with obvious clinical symptoms. In one patient, there was no dizziness in the lying position, but dizziness occurred after changing to the sitting position.