The stability of isoechoic flat plaques is in between that of stable and unstable plaques, and there is a risk of plaque dislodgement, rupture, and a certain degree of danger. Plaques are usually divided into stable and unstable plaques. Stable plaques are more stable, less prone to dislodgement and rupture, and usually show strong echoes on ultrasound, while unstable plaques are more floppy, prone to dislodgement and rupture, and usually show low echoes on ultrasound. The stability of isoechoic flat plaques is in between. Therefore, isoechoic flat plaques have the risk of dislodgment and rupture, which can lead to embolism, organ infarction, and other consequences, and there is a certain degree of danger. Therefore, if isoechoic flat plaques are present, regular follow-up and proper treatment are recommended to avoid the associated adverse consequences.