There is no single cause for the onset of diabetes. The disease may result from a combination of the following physical and environmental factors. Prevention requires balancing the risks.

GENETICS - Type 1 Diabetes is caused by specific genes. There is no specific gene pattern in Type 2 Diabetes, but the chances of developing it increase if other family members have the disease.

ETHNIC BACKGROUND - People of African, Latin American or South Asian descent are five times more likely to develop Type 2 Diabetes than Caucasians.

WEIGHT - Overweight people have an increased risk of developing Type 2 Diabetes because the body's cells become resistant to insulin. Obesity (more than 20 percent above ideal body weight) further increases the chances of developing Type 2 Diabetes.

BODY SHAPE - Carrying excess weight around the waist increases the risk for Type 2 Diabetes.

MEDICATIONS - Some medication can raise blood glucose levels or prevent insulin from working properly, increasing the risk of developing Type 2 Diabetes. These include: steroids such as prednisone and cortisone; thiazide diuretics such as hydrochlorthiazide; beta-blockers such as propranolol; and immunosuppressants such as cyclosporine.

VIRAL INFECTIONS - Specific infections can sometimes set off an abnormal reaction in which the immune system destroys the insulin-producing cells in the pancreas, triggering Type 1 Diabetes.

DAMAGE TO PANCREAS - Conditions such as pancreatitis, cystic fibrosis, hemochromatosis, or removal of the pancreas can lead to the development of diabetes.

HORMONAL DISORDERS - The overproduction of hormones that oppose the action of insulin can cause Type 2 Diabetes.

PREGNANCY - Lack of enough insulin for the fetus during pregnancy results in the temporary condition of gestational diabetes.