Carotid plaque singularity refers to the presence of a single plaque, including vulnerable plaque and non-vulnerable plaque. 1. Vulnerable plaque: refers to unstable plaque that is easy to fall off, and this kind of plaque is a high-risk factor for inducing cardiovascular and cerebrovascular diseases. The causes of vulnerable plaque formation include diabetes, hypertension, hyperlipidemia, etc., platelet aggregation caused by various factors, and inflammatory cell infiltration. Vulnerable plaques are characterized by irregularity and non-smooth surface. 2. Non-vulnerable plaques: Non-vulnerable plaques are plaques that are stable and do not fall off easily. This type of plaque is not likely to cause cardiovascular and cerebrovascular diseases. The surface of this type of plaque is relatively regular and smooth, and it shows isoechoic or strong echogenicity under ultrasound echo. When a single carotid plaque is found, it is recommended to go to the hospital in time, to clarify the cause of the disease under the guidance of the doctor, and to give standardized treatment.