Atherosclerosis[a] is a pattern of the disease arteriosclerosis,[8] characterized by development of abnormalities called lesions in walls of arteries. These lesions may lead to narrowing of the arterial walls due to buildup of atheromatous plaques.[9][10] At onset there are usually no symptoms, but if they develop, symptoms generally begin around middle age.[1] In severe cases, it can result in coronary artery disease, stroke, peripheral artery disease, or kidney disorders, depending on which body part(s) the affected arteries are located in the body.[1]

Reference
Wiki: Hypothyroid atherosclerosis