My mother went for a medical checkup today and was found to have a plaque in her carotid artery, please ask about the severity

I went to the hospital today for a physical examination and found that there is sclerosis in the carotid arteries and small plaques, I am quite worried about the plaques, but the doctor said it is fine without medication, but I would like to ask you all if this is a serious situation and what to pay attention to, thank you.