Known as angiopathy, this is a disease of the blood vessels (arteries, veins, and capillaries) that occurs when someone has diabetes for a long time.

There are two types of angiopathy: macroangiopathy and microangiopathy. In macroangiopathy, fat and blood clots build up in the large blood vessels, stick to the vessel walls, and block the flow of blood. In microangiopathy, the walls of the smaller blood vessels become so thick and weak that they bleed, leak protein, and slow the flow of blood through the body. Then the cells, for example: the ones in the center of the eye, do not get enough blood and may be damaged.