Return to the top of the page. Many of the health problems or complications of diabetes are caused by changes in blood ves-sels. These changes often are brought about by the high glucose levels in a diabetic's blood. Sometimes, changes occur in the large blood vessels, like the veins and arteries. The inside lining becomes thick, reducing the space in the vessel.
Blood has a hard time flowing through.
Heart disease or a stroke can result. Changes can also occur in the small blood vessels, called capillaries, that distribute the blood to individual cells. Damage to the small blood vessels often is most severe in the eyes and kidneys of people with diabetes. When the damaged blood vessels in the eye break open, the eye tissue is injured. High blood glucose levels also damage kidney tissue.