Skip to Content
Type 2 diabetes is a lifelong (chronic) disease in which there is a high level of sugar (glucose) in the blood. Type 2 diabetes is the most common form of diabetes.
Noninsulin-dependent diabetes; Diabetes - type II; Adult-onset diabetes; Diabetic - type 2 diabetes; Oral hypoglycemic - type 2 diabetes; High blood sugar - type 2 diabetes
Insulin is a hormone produced in the pancreas by special cells, called beta cells. The pancreas is below and behind the stomach. Insulin is needed to move blood sugar (glucose) into cells. Inside the cells, glucose is stored and later used for energy.
When you have type 2 diabetes, your fat, liver, and muscle cells do not respond correctly to insulin. This is called insulin resistance. As a result, blood sugar does not get into these cells to be stored for energy.
When sugar cannot enter cells, a high level of sugar builds up in the blood. This is called hyperglycemia. The body is unable to use the glucose for energy. This leads to the symptoms of type 2 diabetes.
Type 2 diabetes usually develops slowly over time. Most people with the disease are overweight or obese when they are diagnosed. Increased fat makes it harder for your body to use insulin the correct way.
Type 2 diabetes can also develop in people who are thin. This is more common in older adults.
Family history and genes play a role in type 2 diabetes. Low activity level, poor diet, and excess body weight around the waist increase your chance of getting the disease.
People with type 2 diabetes often have no symptoms at first. They may not have symptoms for many years.
Early symptoms of diabetes caused by a high blood sugar level may include:
After many years, diabetes can lead to serious health problems, and as a result, many other symptoms.
Your doctor may suspect that you have diabetes if your blood sugar level is higher than 200 milligrams per deciliter (mg/dL) or 11.1 mmol/L. To confirm the diagnosis, one or more of the following tests must be done.
Diabetes screening is recommended for:
If you have been diagnosed with type 2 diabetes, you need to work closely with your doctor. See your doctor as often as instructed. This may be every 3 months.
The following exams and tests will help you and your doctor monitor your diabetes and prevent problems.
Your provider may want to check your vitamin B12 blood levels if you are taking the drug metformin.
At first, the goal of treatment is to lower your high blood glucose level. Long-term goals are to prevent complications. These are health problems that can result from having diabetes.
The most important way to treat and manage type 2 diabetes is by being active and eating healthy foods.
Everyone with diabetes should receive proper education and support about the best ways to manage their diabetes. Ask your doctor about seeing a diabetes nurse educator and a dietitian.
LEARN THESE SKILLS
Learning diabetes management skills will help you live well with diabetes. These skills help prevent health problems and the need for medical care. Skills include:
It may take several months to learn these skills. Keep learning about diabetes, its complications, and how to control and live well with the disease. Stay up-to-date on new research and treatments.
MANAGING YOUR BLOOD SUGAR
Checking your blood sugar level yourself and writing down the results tells you how well you are managing your diabetes. Talk to your doctor and diabetes educator about how often to check.
To check your blood sugar level, you use a device called a glucose meter. Usually, you prick your finger with a small needle, called a lancet. This gives you a tiny drop of blood. You place the blood on a test strip and put the strip into the meter. The meter gives you a reading that tells you the level of your blood sugar.
Your doctor or diabetes educator will help set up a testing schedule for you. Your doctor will help you set a target range for your blood sugar numbers. Keep these factors in mind:
Keep a record of your blood sugar for yourself and your doctor. Based on your numbers, you may need to make changes to your meals, activity, or medicines to keep your blood sugar level in the right range.
HEALTHY EATING AND WEIGHT CONTROL
Work closely with your health care providers to learn how much fat, protein, and carbohydrates you need in your diet. Your meal plans should fit your lifestyle and habits and should include foods that you like.
Managing your weight and having a well-balanced diet are important. Some people with type 2 diabetes can stop taking medicines after losing weight. This does not mean that their diabetes is cured. They still have diabetes.
Obese people whose diabetes is not well managed with diet and medicine may consider weight loss (bariatric) surgery.
REGULAR PHYSICAL ACTIVITY
Regular activity is important for everyone. It is even more important when you have diabetes. Exercise is good for your health because it:
Talk to your doctor before starting any exercise program. People with type 2 diabetes may need to take special steps before, during, and after physical activity or exercise.
MEDICINES TO TREAT DIABETES
If diet and exercise do not help keep your blood sugar at normal or near-normal levels, your doctor may prescribe medicine. Since these drugs help lower your blood sugar level in different ways, your doctor may have you take more than one drug.
Some of the most common types of medicines are listed below. They are taken by mouth or injection.
You may need to take insulin if your blood sugar cannot be controlled with any of the above medicines. Most commonly, insulin is injected under the skin using a syringe, insulin pen, or pump. Another form of insulin is the inhaled type. Insulin cannot be taken by mouth because the acid in the stomach destroys the insulin.
Your doctor may prescribe medicines or other treatments to reduce your chance of developing some of the more common complications of diabetes, including:
People with diabetes are more likely than those without diabetes to have foot problems. Diabetes damages the nerves. This can make your feet less able to feel pressure, pain, heat, or cold. You may not notice a foot injury until you have severe damage to the skin and tissue below, or you get a severe infection.
Diabetes can also damage blood vessels. Small sores or breaks in the skin may become deeper skin sores (ulcers). The affected limb may need to be amputated if these skin ulcers do not heal or become larger, deeper, or infected.
To prevent problems with your feet:
Living with diabetes can be stressful. You may feel overwhelmed by everything you need to do to manage your diabetes. But taking care of your emotional health is just as important as your physical health.
Ways to relieve stress include:
Feeling sad or down (depressed) or anxious sometimes is normal. But if you have these feelings often and they're getting in the way of managing your diabetes, talk with your health care team. They can find ways to help you feel better.
There are many diabetes resources that can help you understand more about type 2 diabetes. You can also learn ways to manage your condition so you can live well with diabetes.
Diabetes is a lifelong disease and there is no cure.
Some people with type 2 diabetes no longer need medicine if they lose weight and become more active. When they reach their ideal weight, their body's own insulin and a healthy diet can control their blood sugar level.
After many years, diabetes can lead to serious health problems:
Call 911 right away if you have:
These symptoms can quickly get worse and become emergency conditions (such as convulsions, hypoglycemic coma or hyperglycemic coma).
Also call your doctor if you have:
You can help prevent type 2 diabetes by staying at a healthy body weight. You can get to a healthy weight by eating healthy foods, controlling your portion sizes, and leading an active lifestyle. Some medicines can also delay or prevent type 2 diabetes in people at risk of developing the disease.
American Diabetes Association. Standards of medical care in diabetes – 2017. Diabetes Care. 2017;40(Suppl 1):S1-S98. care.diabetesjournals.org/content/40/Supplement_1.
Cagliero E. Diabetes and long-term complications. In: Jameson JL, De Groot LJ, de Kretser DM, et al, eds. Endocrinology: Adult and Pediatric. 7th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 51.
Moustarah F, Brethauer SA, Schauer PR. Glycemic control and cardiovascular disease risk reduction after bariatric surgery. In: Cameron JL, Cameron AM, eds. Current Surgical Therapy. 11th ed. Philadelphia, PA: Elsevier Saunders; 2014:682-691.
Polonsky KS, Burant CF. Type 2 diabetes mellitus. In: Melmed S, Polonsky KS, Burant, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology. 13th ed. Philadelphia, PA: Elsevier; 2016:chap 31.
Vijan S. In the clinic. Type 2 diabetes. Ann Intern Med. 2015;162(5):ITC1-ITC16. PMID: 25732301 www.ncbi.nlm.nih.gov/pubmed/25732301.
Reviewed By: Robert Hurd, MD, Professor of Endocrinology and Health Care Ethics, Xavier University, Cincinnati, OH. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.