Type 1 and type 2 diabetes share the problem of high levels of blood sugar. The inability to control blood sugar causes the symptoms and the complications of both types of diabetes. But type 1 diabetes and type 2 diabetes are two different diseases in many ways. According to the latest (2014) estimates from the Centers for Disease Control and Prevention (CDC), 29.1 million people, or 9.3 percent of the U.S. population, have diabetes. Type 1 diabetes affects just 5 percent of those adults, with type 2 diabetes affecting up to 95 percent.