Arteriosclerosis is a disease of cardiovascular system and involves any type of thickening and loss of elasticity of the arterial wall. There are three main types: atherosclerosis (the most common type), Mönckeberg arteriosclerosis, and arteriolosclerosis. Healthy arteria consist out of 3 layers: inner layer (tunica intima), middle layer (tunica media) and outer layer (tunica adventitia). Arteriosclerosis differs from atherosclerosis by position of disease development inside of the arterial wall. Only in atherosclerosis an inflammatory processes occur. It comes to activation of T-cells and macrophages, smooth muscle cells proliferate and migrate, and in the end it comes to endothelium disfunction. On the other hand smooth muscle cells are affected mostly by artheriosclerosis, weather immune system cells do not play an important role. When disease comes to the end stage where vessels are completely narrowed, lipid clusters on the arteria walls can come off and create blood clots. If the clot comes to the heart or the brain, it can cause severe damage and even death. Arteriosclerosis is being studied for a long time, mostly because there is no general treatment. If the condition is not that severe pacients are recomended to eat healthy, be physically active, avoid smoking and drinking and sometimes take drugs which can help maintain current stage and stop progression of the disease. For studying disease initiation, development and regression natural animal models are frequently used. The most common among them are fishes, but mice, rabbits, pigs and non-human primates are also very good.