The information on this page is intended for general background informational purposes only. Diabetes patients should visit Health Topics A-Z for the U-M's patient education handout in accordance with clinical care guidelines.

Type 2 Diabetes Mellitus
Also known as adult diabetes, non-insulin-dependent diabetes mellitus, and NIDDM

What is type 2 diabetes

Type 2 diabetes is the most common form of diabetes. It accounts for approximately 90 percent of all diabetes cases. It is a disorder that occurs when the body does not make enough insulin or is unable to use insulin effectively. Some individuals with type 2 diabetes make large amounts of insulin, but are resistant to its action. This problem with insulin causes the level of sugar in the blood to become abnormally high.

During digestion, the body breaks down food into sugar (or glucose) which the blood carries to the cells. Insulin's job is to help the sugar leave the bloodstream and enter the cells where it can be used for energy. When the body does not have enough insulin, sugar can't get into the cells and, instead, builds up in the bloodstream. The body is unable to use the sugar for energy despite having high levels of it in the bloodstream and the result is high blood sugar levels and diabetes. If not treated, diabetes can cause severe long-term health problems including heart disease, stroke, blindness, kidney failure, and nerve damage, especially to feet and legs.

Type 2 diabetes typically occurs in overweight adults over age 40, but it also can manifest in overweight children and adolescents.

Causes

The exact cause of type 2 diabetes is unknown, but age, weight, and exercise level appear to be important factors. As people become older, sedentary, or overweight, they are more likely to have diabetes. Their cells become unable to use the insulin made by the pancreas.

Heredity and ethnic background also play a major role. Native Americans, Latinos, African Americans and Asian Americans are at greater risk for diabetes. Additionally, women who have given birth to large babies (weighing nine or more pounds) or who have had diabetes during pregnancy also have a higher risk of developing diabetes later in life.

Symptoms

People with type 2 diabetes may experience the following symptoms. It is important to note that most people with type 2 diabetes have no symptoms, especially at first.

• Increased urination
• Increased thirst
• Increased appetite
• Unexpected weight gain or weight loss
• Blurred vision
• Skin infections
• Vaginal infections
• Fatigue
• Slowly healing sores
• Abnormal feelings of prickling, burning, or itching of the skin, usually on the hands or feet

Tests and diagnosis

The following tests are used to diagnose type 2 diabetes:

• Blood sugar (or glucose) test:
• A fasting blood glucose of 126 mg/dL or higher indicates diabetes
• A random (non-fasting) blood glucose that exceeds 200 mg/dL indicates diabetes, but this must be confirmed with a fasting test

Is type 2 diabetes preventable?

Even if there is a family history of diabetes, you can reduce your risk by staying active, eating healthy, and maintaining a reasonable weight. Data suggests that moderate exercise (i.e. walking five days a week for 30 minutes each day) lowers risk, as does losing five to 10 percent of your bodyweight if you are overweight.

How long will type 2 diabetes last?

Increased activity and weight loss may help the body use insulin more effectively, but the condition is chronic and lasts a lifetime.

Treatment and care

Research has shown that control of blood sugar, blood pressure and cholesterol values can dramatically decrease the risk for long term complications in people with type 2 diabetes. The major goal in managing this disorder is keeping blood sugar levels as close to normal as safe and possible. Medication, education, meal planning, weight control, exercise, foot care, and self-testing of blood glucose levels are vital to successful treatment.

•  Medication

Pills are not insulin, but they help the pancreas make more insulin or use it more effectively. Most patients may need more than one type of medication to keep blood sugar in the normal range.

Insulin is prescribed when diet, exercise, and oral medicines are not enough to normalize blood sugar levels. A major component of insulin therapy is knowing how to self-check blood sugar levels since blood sugar tests give information about how well a treatment balance is working.

•  Meal planning
Eating nutritionally balanced meals at regular times and in consistent amounts helps control blood sugar. A health provider or dietitian can provide specific guidelines about how to eat the foods you like and are important to you, as well as balance your blood sugar. Overweight individuals are encouraged to lose weight to decrease blood sugar. Sometimes losing just seven to 10 pounds can reduce or eliminate the need for medication.

•  Activity
Physical activity lowers blood sugar and blood pressure, improves circulation, lowers cholesterol, helps the body use insulin more efficiently, and helps people cope with stress. In some cases, exercise is all some diabetics need to control their blood sugar. Obtain advice and medical approval from a health care provider before beginning any exercise program.

•  Education
Learning how to care for and live with diabetes are necessary to avoid developing complications such as diabetic retinopathy (eye disease) or nephropathy (kidney disease).

Education classes are available through the University of Michigan Health System, the local American Diabetes Association, and others. Talk to a health care provider for details.

•  Foot Care
Since diabetes causes damage to the blood vessels and nerves which can result in a decreased ability to sense trauma or pressure on the foot, people with diabetes are prone to foot problems. A foot injury could go unnoticed until severe infection develops. Additionally, diabetes alters the body's immune system and decreases the body's ability to fight infection. Small infections can rapidly progress to the severe damage of skin and other tissues. The result could be amputation of the affected limb. Examining feet each day for signs of injury, wearing well-fitting shoes, and treating problems quickly can dramatically lower risk.

•  Emotional Care
Whether you are newly diagnosed or you have had type 2 diabetes for some time, it is common to have many thoughts and feelings about this disease and all that needs to be done to manage it successfully. Some very common feelings are anger, fear, sadness, and “why me?” One of the most helpful things you can do is find a good listener – someone you can talk with about your feelings and who will listen without making judgments or offering advice. Your spouse, health care provider or diabetes educator, a family member, or a good friend may be this person for you. Some people find it helpful to go to a support group made up of people with diabetes and their family members. They understand what you are going through and often have experiences to share that will benefit you.

While some negative feelings are to be expected, if these feelings become overwhelming or are affecting your ability to care for yourself or participate in your usual activities, talk with your provider, even if you aren't asked about this issue. There are treatments available that work and will help.

Next - Treatment goals >>

Additional sources: National Institutes of Health and the American Diabetes Association