Type 1 and Type 2
Understanding diabetes starts with knowing the different types of diabetes and their key differences. The two most common types are type 1 and type 2.
Type 1 diabetes
In type 1 diabetes, the body makes little or no insulin due to an overactive immune system. So people with type 1 diabetes must take insulin every day. Type 1 diabetes usually occurs in children and young adults but can also appear in older adults.
Type 2 diabetes
In type 2 diabetes, your body prevents the insulin it does make from working right. Your body may make some insulin but not enough. Most people with diabetes—about 90% to 95%—have type 2. This kind of diabetes usually happens in people who are older, although even younger adults may be diagnosed with it. Type 2 diabetes also usually occurs in people who are overweight. In fact, about 8 out of 10 people with type 2 diabetes are overweight.
Diabetes during pregnancy (gestational diabetes)
Some women may develop diabetes during pregnancy, which is called gestational diabetes. Being diagnosed with gestational diabetes doesn't mean a woman had diabetes before or would continue to have diabetes after giving birth. A woman should follow her health care provider's advice closely during pregnancy.