A disease that occurs when the body is not able to use sugar as it should. The body changes carbohydrates into glucose. A hormone called insulin is needed for the glucose to be taken up and used by tissues. Diabetes occurs when the body cannot make use of the glucose in the blood for energy because either the pancreas is not able to make enough insulin or the insulin that is available is not effective. The beta cells in areas of the pancreas called the islets of Langerhans usually make insulin. The signs of diabetes include having to urinate often, losing weight, getting very thirsty, and being hungry all the time. Other signs are blurred vision, itching, and slow healing of sores. People with untreated or undiagnosed diabetes are thirsty and have to urinate often because glucose builds to a high level in the bloodstream and the kidneys are working hard to flush out the extra amount. People with untreated diabetes often get hungry and tired because the body is not able to use food the way it should. The causes of diabetes are not known. Scientists think that insulin- dependent diabetes may be more than one disease and may have many causes. They are looking at genetic factors and at other factors, including viruses.