On this page:
Type 2 diabetes, the most common type of diabetes, is a disease that occurs when your blood glucose, also called blood sugar, is too high. Blood glucose is your main source of energy and comes mainly from the food you eat. Insulin, a hormone made by the pancreas, helps glucose get into your cells to be used for energy. In type 2 diabetes, your body doesn’t make enough insulin or doesn’t use insulin well. Too much glucose then stays in your blood, and not enough reaches your cells.
The good news is that you can take steps to prevent or delay the development of type 2 diabetes.
You can develop type 2 diabetes at any age, even during childhood. However, type 2 diabetes occurs most often in middle-aged and older people. You are more likely to develop type 2 diabetes if you are age 45 or older, have a family history of diabetes, or are overweight or obese. Diabetes is more common in people who are African American, Hispanic/Latino, American Indian, Asian American, or Pacific Islander.
Physical inactivity and certain health problems such as high blood pressure affect your chances of developing type 2 diabetes. You are also more likely to develop type 2 diabetes if you have prediabetes or had gestational diabetes when you were pregnant. Learn more about risk factors for type 2 diabetes.
Symptoms of diabetes include
Symptoms of type 2 diabetes often develop slowly—over the course of several years—and can be so mild that you might not even notice them. Many people have no symptoms. Some people do not find out they have the disease until they have diabetes-related health problems, such as blurred vision or heart disease.
Type 2 diabetes is caused by several factors, including
Learn more about the causes of type 2 diabetes.
Your health care professional can diagnose type 2 diabetes based on blood tests. Learn more about blood tests for diabetes and what the results mean.
Managing your blood glucose, blood pressure, and cholesterol, and quitting smoking if you smoke, are important ways to manage your type 2 diabetes. Lifestyle changes that include planning healthy meals, limiting calories if you are overweight, and being physically active are also part of managing your diabetes. So is taking any prescribed medicines. Work with your health care team to create a diabetes care plan that works for you.
Along with following your diabetes care plan, you may need diabetes medicines, which may include pills or medicines you inject under your skin, such as insulin. Over time, you may need more than one diabetes medicine to manage your blood glucose. Even if you don’t take insulin, you may need it at special times, such as during pregnancy or if you are in the hospital. You also may need medicines for high blood pressure, high cholesterol, or other conditions.
Learn more about medicines, insulin, and other diabetes treatments.
Following a good diabetes care plan can help protect against many diabetes-related health problems. However, if not managed, diabetes can lead to problems such as
Many people with type 2 diabetes also have nonalcoholic fatty liver disease (NAFLD). Losing weight if you are overweight or obese can improve NAFLD. Diabetes is also linked to other health problems such as sleep apnea, depression, some types of cancer, and dementia.
You can take steps to lower your chances of developing these diabetes-related health problems.
Research such as the Diabetes Prevention Program, sponsored by the National Institutes of Health, has shown that you can take steps to reduce your chances of developing type 2 diabetes if you have risk factors for the disease. Here are some things you can do to lower your risk:
Ask your health care team what other changes you can make to prevent or delay type 2 diabetes.
Most often, your best chance for preventing type 2 diabetes is to make lifestyle changes that work for you long term. Get started with Your Game Plan to Prevent Type 2 Diabetes.
This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. The NIDDK translates and disseminates research findings through its clearinghouses and education programs to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by the NIDDK is carefully reviewed by NIDDK scientists and other experts.
The NIDDK would like to thank:
Rita Basu, M.D., Mayo Clinic