Atherosclerosis or Arteriosclerotic Vascular Disease (ASVD) is a disease affecting the arterial blood vessels. It is a chronic inflammatory response in the walls of arteries, in large part due to the accumulation macrophage white blood cells and promoted by low density (especially small particle) lipoproteins (plasma proteins that carry cholsterol) without adequate removal of fats and cholesterol from the macrophages by functional high density lipoproteins. It is commonly referred to as a "hardening" or "furring" of the arteries. It is caused by the formation of multiple plaques within the arteries. Atherosclerosis is a form of arteriosclerosis .