Difference between Type I & Type II

Type 1: 

In type 1 diabetes (formerly called insulin-dependent diabetes or juvenile-onset diabetes); more than 90% of the insulin-producing cells of the pancreas are permanently destroyed. The pancreas, therefore, produces little or no insulin. Only about 10% of all people with diabetes have type 1 disease. Most people who have type 1 diabetes develop the disease before age 30.

Scientists believe that an environmental factor—possibly a viral infection or a nutritional factor in childhood or early adulthood—causes the immune system to destroy the insulin-producing cells of the pancreas. A genetic predisposition may make some people more susceptible to the environmental factor.

Type 2: 

In type 2 diabetes (formerly called non-insulin-dependent diabetes or adult-onset diabetes), the pancreas continues to produce insulin, sometimes even at higher-than-normal levels. However, the body develops resistance to the effects of insulin, so there is not enough insulin to meet the body's needs.

Type 2 diabetes was once rare in children and adolescents but has recently become more common. However, it usually begins in people older than 30 and becomes progressively more common with age. About 15% of people older than 70 have type 2 diabetes. Type 2 diabetes also tends to run in families.

Obesity is the chief risk factor for developing type 2 diabetes, and 80 to 90% of people with this disorder are overweight or obese. Because obesity causes insulin resistance, obese people need very large amounts of insulin to maintain normal blood sugar levels.