Vascular disease progression. Artwork showing the progression of vascular disease in cross-section (left) and transverse section (right). At top is a healthy artery. Below this, fat (yellow) is beginning to accumulate and circulate in the blood. In the blood vessel at centre, fatty deposits (atheroma) have been laid down on the inner wall of the vessel, which leads to inflammation of the underlying muscle cells (purple area in fourth artery) and a narrowed blood vessel. In the bottom blood vessel the plaque has ruptured. This leads to a blood clot and reduction in blood flow (ischaemia) to the tissue supplied by the vessel. If the vessel is in the heart this can lead to a heart attack, if it is in the brain is can lead to a stroke.