With type 2 diabetes, the more common type, your body does not make or use insulin well.
Diabetes means your blood glucose, or blood sugar, levels are too high. With type 2 diabetes, the more common type, your body does not make or use insulin well. Insulin is a hormone that helps glucose get into your cells to give them energy. Without insulin, too much glucose stays in your blood. Over time, high blood glucose can lead to serious problems with your heart, eyes, kidneys, nerves, and gums and teeth.
You have a higher risk of type 2 diabetes if you are older, obese, have a family history of diabetes, or do not exercise. Having prediabetes also increases your risk. Prediabetes means that your blood sugar is higher than normal but not high enough to be called diabetes.
Type 2 diabetes is thought to be caused by a combination of genetic and environmental factors. (See "Pathogenesis of type 2 diabetes mellitus" and "Risk factors for type 2 diabetes mellitus".)
- Many people with diabetes type 2 have a family member with either diabetes type 2 or other medical problems associated with diabetes, such as high cholesterol levels, high blood pressure, or obesity.
- The lifetime risk of developing diabetes type 2 is 5 to 10 times higher in first-degree relatives (sister, brother, son, daughter) of a person with diabetes compared with a person with no family history of diabetes.
The likelihood of developing diabetes type 2 is greater in certain ethnic groups, such as people of Hispanic, African, and Asian descent.
Environmental factors such as what you eat and how active you are, combined with genetic causes, affect the risk of developing diabetes type 2.
A small number (about 3 to 5 percent) of pregnant women develop diabetes during pregnancy, called "gestational diabetes." Gestational diabetes is similar to diabetes type 2, but usually resolves after the woman delivers her baby. Women who have gestational diabetes are at increased risk for developing diabetes type 2 later in life.
The symptoms of diabetes type 2 appear slowly. Some people do not notice symptoms at all. The symptoms can include
- Being very thirsty
- Urinating often
- Feeling very hungry or tired
- Losing weight without trying
- Having sores that heal slowly
- Having blurry eyesight
Blood tests can show if you have diabetes. One type of test, the A1C, can also check on how you are managing your diabetes.
Many people can manage their diabetes through healthy eating physical activity, and blood glucose testing. Some people also need to take diabetes medicines.