Atheroma
（重定向自Microatheroma）
![](/Images/godic/202501/27/Carotid_Plaque3428.jpg")
![Illustration comparing a normal blood vessel and partially blocked vessel due to atherosclerotic plaque. Notice the enlargement & absence of much luminal narrowing.[5]](/Images/godic/202501/27/Blausen_0052_Artery_NormalvPartially-BlockedVessel3428.png")
![A commonly promoted and misleading illustration of artery plaque.](/Images/godic/202501/27/Artery_Plaque3428.png")
An atheroma is an accumulation of degenerative material in the tunica intima (inner layer) of artery walls. The material consists of (mostly) macrophage cells, or debris, containing lipids (cholesterol and fatty acids), calcium and a variable amount of fibrous connective tissue. The accumulated material forms a swelling in the artery wall, which may intrude into the channel of the artery, narrowing it and restricting blood flow. Atheroma occurs in atherosclerosis, which is one of the three subtypes of arteriosclerosis (which are atherosclerosis, Monckeberg's arteriosclerosis and arteriolosclerosis).