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What is type 2 diabetes?
Type 2 diabetes is a disease in which your blood glucose, or blood sugar, levels are too high. Glucose is your main source of energy. It comes from the foods you eat. A hormone called insulin helps the glucose get into your cells to give them energy. If you have diabetes, your body doesn't make enough insulin or doesn't use insulin well. The glucose then stays in your blood and not enough goes into your cells.
Over time, having too much glucose in your blood can cause health problems. But you can take steps to manage your diabetes and try to prevent these health problems.
What causes type 2 diabetes?
Type 2 diabetes may be caused by a combination of factors:
- Being overweight or having obesity
- Not being physically active
- Genetics and family history
Type 2 diabetes usually starts with insulin resistance. This is a condition in which your cells don't respond normally to insulin. As a result, your body needs more insulin to help the glucose enter your cells. At first, your body makes more insulin to try to get cells to respond. But over time, your body can't make enough insulin, and your blood glucose levels rise.
Who is at risk for type 2 diabetes?
You are at higher risk of developing type 2 diabetes if you:
- Are over age 45. Children, teenagers, and younger adults can get type 2 diabetes, but it is more common in middle-aged and older people.
- Have prediabetes, which means that your blood sugar is higher than normal but not high enough to be called diabetes
- Had diabetes in pregnancy or gave birth to a baby weighing 9 pounds or more.
- Have a family history of diabetes
- Are overweight or have obesity
- Are Black or African American, Hispanic/Latino, American Indian, Asian American, or Pacific Islander
- Are not physically active
- Have other conditions such as high blood pressure, heart disease, stroke, polycystic ovary syndrome (PCOS), or depression
- Have low HDL (good) cholesterol and high triglycerides
- Have acanthosis nigricans - dark, thick, and velvety skin around your neck or armpits
What are the symptoms of type 2 diabetes?
Many people with type 2 diabetes have no symptoms at all. If you do have them, the symptoms develop slowly over several years. They might be so mild that you do not notice them. The symptoms can include:
- Increased thirst and urination
- Increased hunger
- Feeling tired
- Blurred vision
- Numbness or tingling in the feet or hands
- Sores that do not heal
- Unexplained weight loss
How is type 2 diabetes diagnosed?
Your health care provider will use blood tests to diagnose type 2 diabetes. The blood tests include:
- A1C test, which measures your average blood sugar level over the past 3 months
- Fasting plasma glucose (FPG) test, which measures your current blood sugar level. You need to fast (not eat or drink anything except water) for at least 8 hours before the test.
- Random plasma glucose (RPG) test, which measures your current blood sugar level. This test is used when you have diabetes symptoms and the provider does not want to wait for you to fast before having the test.
What are the treatments for type 2 diabetes?
Treatment for type 2 diabetes involves managing your blood sugar levels. Many people are able to do this by living a healthy lifestyle. Some people may also need to take medicine:
- A healthy lifestyle includes following a healthy eating plan and getting regular physical activity. You need to learn how to balance what you eat and drink with physical activity and diabetes medicine, if you take any.
- Medicines for diabetes include oral medicines, insulin, and other injectable medicines. Over time, some people will need to take more than one type of medicine to control their diabetes.
- You will need to check your blood sugar regularly. Your health care provider will tell you how often you need to do it.
- It's also important to keep your blood pressure and cholesterol levels close to the targets your provider sets for you. Make sure to get your screening tests regularly.
Can type 2 diabetes be prevented?
You can take steps to help prevent or delay type 2 diabetes by losing weight if you are overweight, eating fewer calories, and being more physically active. If you have a condition which raises your risk for type 2 diabetes, managing that condition may lower your risk of getting type 2 diabetes.
NIH: National Institute of Diabetes and Digestive and Kidney Diseases
Diagnosis and Tests
- A1C: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish
- Diabetes Tests (National Library of Medicine) Also in Spanish
- Diabetes Tests and Diagnosis (National Institute of Diabetes and Digestive and Kidney Diseases) Also in Spanish
- Insulin in Blood (National Library of Medicine) Also in Spanish
- Ketones in Blood (National Library of Medicine) Also in Spanish
- Ketones in Urine (National Library of Medicine) Also in Spanish
Prevention and Risk Factors
- Find a Lifestyle Change Program (Centers for Disease Control and Prevention)
- How to Prevent Diabetes: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish
Treatments and Therapies
- Diabetes and Dietary Supplements: What You Need to Know (National Center for Complementary and Integrative Health) Also in Spanish
- Diabetes Medicines: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish
- Women and Diabetes -- Diabetes Medicines (Food and Drug Administration)
Living With
- Changing Your Habits for Better Health (National Institute of Diabetes and Digestive and Kidney Diseases) Also in Spanish
- Diabetes and Mental Health (Centers for Disease Control and Prevention) Also in Spanish
- Diabetic Diet: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish
- Healthy Weight (Centers for Disease Control and Prevention) Also in Spanish
- How to Stay Healthy With Type 2 Diabetes (Nemours Foundation) Also in Spanish
- Managing Diabetes (National Institute of Diabetes and Digestive and Kidney Diseases) Also in Spanish
- Your Diabetes Care Team (Mayo Foundation for Medical Education and Research) Also in Spanish
Related Issues
- 5 Things To Know About Type 2 Diabetes and Dietary Supplements (National Center for Complementary and Integrative Health)
- Acanthosis Nigricans (Mayo Foundation for Medical Education and Research) Also in Spanish
- Healthy Living with Diabetes (National Institute of Diabetes and Digestive and Kidney Diseases) Also in Spanish
- National Diabetes Prevention Program (Centers for Disease Control and Prevention)
- Prediabetes:MedlinePlus Health Topic (National Library of Medicine) Also in Spanish
- Speak Up -- Diabetes: Five Ways to Be Active in Your Care at the Hospital (Joint Commission) - PDF
- Symptoms and Causes of Diabetes (National Institute of Diabetes and Digestive and Kidney Diseases) Also in Spanish
Specifics
- Hyperinsulinemia: Is it diabetes? (Mayo Foundation for Medical Education and Research) Also in Spanish
Genetics
- Genetics of Diabetes (American Diabetes Association)
- Type 2 diabetes: MedlinePlus Genetics (National Library of Medicine)
Health Check Tools
- Type 2 Diabetes Risk Test (American Diabetes Association)
Test Your Knowledge
- Type 2 Diabetes: How Healthy Is Your Lifestyle? (Medical Encyclopedia) Also in Spanish
Statistics and Research
- Diabetes Drug May Reduce Colorectal Cancer Risk (National Institutes of Health) Also in Spanish
- Diabetes in America, 3rd Edition (National Institute of Diabetes and Digestive and Kidney Diseases)
- National Diabetes Statistics Report (Centers for Disease Control and Prevention)
Clinical Trials
- ClinicalTrials.gov: Diabetes Mellitus, Type 2 (National Institutes of Health)
Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)
Find an Expert
- American Diabetes Association
- National Institute of Diabetes and Digestive and Kidney Diseases
- NIDDK Information Clearinghouses and Health Information Center (National Institute of Diabetes and Digestive and Kidney Diseases)
- Search Diabetes Educator Directory (Association of Diabetes Care and Education Specialists)
Older Adults
- Diabetes (AGS Health in Aging Foundation)
- Diabetes in Older People (National Institute on Aging) Also in Spanish
Patient Handouts
- A1C test (Medical Encyclopedia) Also in Spanish
- Diabetes type 2 - meal planning (Medical Encyclopedia) Also in Spanish
- Giving an insulin injection (Medical Encyclopedia) Also in Spanish
- High blood sugar - self-care (Medical Encyclopedia) Also in Spanish
- Type 2 diabetes - self-care (Medical Encyclopedia) Also in Spanish
The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.