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Type 2 diabetes

Contents of this page:


Diabetes and exercise
Diabetes and exercise
Diabetic emergency supplies
Diabetic emergency supplies
Low blood sugar symptoms
Low blood sugar symptoms
15/15 rule
15/15 rule
Starchy foods
Starchy foods
Glucose in blood
Glucose in blood
Alpha-glucosidase inhibitors
Alpha-glucosidase inhibitors
Sulfonylureas drug
Sulfonylureas drug
Food and insulin release
Food and insulin release
Monitor blood glucose - series
Monitor blood glucose - series

Alternative Names    Return to top

Noninsulin-dependent diabetes; Diabetes - type 2; Adult-onset diabetes

Definition    Return to top

Type 2 diabetes is a chronic (lifelong) disease marked by high levels of sugar in the blood. It begins when the body does not respond correctly to insulin, a hormone released by the pancreas. Type 2 diabetes is the most common form of diabetes.

See also:

Causes    Return to top

Diabetes is caused by a problem in the way your body makes or uses insulin. Insulin is needed to move glucose (blood sugar) into cells, where it is used for energy.

If glucose does not get into the cells, the body cannot use it for energy. Too much glucose will stay in the blood, causing the symptoms of diabetes.

There are several types of diabetes. This article focuses on type 2, which usually occurs with obesity and insulin resistance.

Insulin resistance means that fat, liver and muscle cells do not respond normally to insulin. As a result they do not store sugar for energy. Since the tissues do not respond well to insulin, the pancreas produces more and more insulin.

Because sugar is not getting into the tissues, abnormally high levels of sugar build up in the blood. This is called hyperglycemia. Many people with insulin resistance have hyperglycemia and high blood insulin levels at the same time. People who are overweight have a higher risk of insulin resistance, because fat interferes with the body's ability to use insulin.

Type 2 diabetes usually occurs gradually. Most people with the disease are overweight at the time of diagnosis. However, type 2 diabetes can also develop in those who are thin, especially the elderly.

Family history and genetics play a large role in type 2 diabetes. Low activity level, poor diet, and excess body weight (especially around the waist) significantly increase your risk for type 2 diabetes.

Other risk factors include:

Symptoms    Return to top

Often, people with type 2 diabetes have no symptoms at all. If you do have symptoms, they may include:

Exams and Tests    Return to top

Type 2 diabetes is diagnosed with the following blood tests:

Have your hemoglobin A1c (HbA1c) level checked every 3 - 6 months. The HbA1c is a measure of average blood glucose during the past 2 -3 months. It is a very helpful way to determine how well treatment is working.

Treatment    Return to top

The immediate goal of treatment is to lower high blood glucose levels. The long-term goals of treatment are to prevent diabetes-related complications, such as:

The primary treatment for type 2 diabetes is exercise and diet.


You should learn basic diabetes management skills. They will help prevent complications and the need for medical care. These skills include:

It may take several months to learn the basic skills. Always continue to educate yourself about the disease and its complications. Learn how to control and live with diabetes. Over time, stay current on new research and treatment.


Regular self-testing of your blood sugar tells you how well your combination of diet, exercise, and medication are working. Tests are usually done before meals and at bedtime. More frequent testing may be needed when you are sick or under stress.

A device called a glucometer can provide an exact blood sugar reading. There are different types of devices. 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 device. Results are available in 30 - 45 seconds.

A health care provider or diabetes educator will help set up an appropriate testing schedule for you. You will also be taught how to respond to different ranges of glucose values when you self-test.

The results of the test can be used to adjust meals, activity, or medications to keep your blood sugar levels in an appropriate range. Testing provides valuable information for the health care provider. It can identify high and low blood sugar levels before serious problems develop.

Keeping accurate records of test results will help you and your health care provide plan how to best control your diabetes.


Meal planning includes choosing healthy foods, eating the right amount of food, and eating meals at the right time. You should work closely with your health care provider to learn how much fat, protein, and carbohydrates you need in your diet. Your specific meal plans need to be tailored to your food habits and preferences.

Managing your weight and eating a well-balanced diet are important. Some people with type 2 diabetes can stop taking medications after losing weight (although the diabetes is still there). A registered dietitian can help determine your dietary needs. (See diabetes diet)


Regular exercise is important for everyone, but especially if you have diabetes. Regular exercise helps control the amount of glucose in the blood. It also helps burn excess calories and fat so you can manage your weight.

Exercise can help your overall health by improving blood flow and blood pressure. It decreases insulin resistance even without weight loss. Exercise also increases the body's energy level, lowers tension, and improves your ability to handle stress.

Consider the following when starting an exercise routine:


When diet and exercise do not help maintain normal or near-normal blood glucose levels, your doctor may prescribe medication. Most people with type 2 diabetes will eventually need more than one medication to maintain good blood sugar control. Different groups of medications may be combined or used with insulin.

Some of the most common types of medication are listed below. They are taken by mouth or injection.

If you continue to have poor blood glucose control despite lifestyle changes and taking medicines by mouth, your doctor will prescribe insulin. Insulin may also be prescribed if you have had a bad reaction to other medicines. Insulin must be injected under the skin using a syringe. It cannot be taken by mouth.

Insulin preparations differ in how fast they start to work and how long they work. Your healthcare provider will determine the appropriate type of insulin to use and will tell you what time of day to use it.

More than one type may be mixed together in an injection to achieve the best blood glucose control. Usually injections are needed one to four times a day. Your doctor or diabetes educator will show you how to give yourself an injection.

Some people with type 2 diabetes find they no longer need medication if they lose weight and increase activity. When they reach their ideal weight, their own insulin and a careful diet can control their blood glucose levels.

It is not known whether hypoglycemia medications taken by mouth are safe for use in pregnancy. Women who have type 2 diabetes and take these medications may be switched to insulin during pregnancy and while breastfeeding.


People with diabetes are more likely to have foot problems. Diabetes can damage nerves, which means you may not feel an injury to the foot until a large sore or infection develops. Diabetes can also damage blood vessels.

In addition, diabetes affects the body's immune system. This decreases the body's ability to fight infection. Small infections can quickly get worse and cause the death of skin and other tissues. Amputation may be needed.

To prevent injury to the feet, check and care for your feet every day.

See also: Diabetes foot care


A person with type 2 diabetes should visit a diabetes care provider every 3 months. A complete examination includes:

The following evaluations should be done at least once a year:

Support Groups    Return to top

For additional information, see diabetes resources.

Outlook (Prognosis)    Return to top

The risk of long-term complications from diabetes can be reduced. If you control your blood glucose and blood pressure, you can reduce your risk of death, stroke, heart failure, and other complications. Reduction of HbA1c by even 1% can decrease your risk for complications by 25%.

Possible Complications    Return to top

Emergency complications include diabetic coma.

Long-term complications include:

When to Contact a Medical Professional    Return to top

Call your health care provider immediately if you have:

These symptoms can quickly get worse and become emergency conditions (such as convulsions, unconsciousness, or hypoglycemic coma).

Prevention    Return to top

Screening for type 2 diabetes and people with no symptoms is recommended for:

Maintain a healthy body weight and keep an active lifestyle to help prevent type 2 diabetes.

To prevent complications of diabetes, visit your health care provider or diabetes educator at least four times a year. Talk about any problems you are having.

Regularly have the following tests:

Stay up-to-date with all of your vaccinations and get a flu shot every year in the fall.

References    Return to top

American Diabetes Association. Standards of medical care in diabetes -- 2008. Diabetes Care. 2008/31:S12-S54.

American Diabetes Association (ADA). Standards of medical care in diabetes IV. Prevention/delay of type 2 diabetes. Diabetes Care. 2007;30:S7-S8.

In the clinic. Type 2 diabetes. Ann Intern Med. 2007;146:ITC-1-15.

Psaty BM, Furberg CD. Rosiglitazone and Cardiovascular Risk. N Engl J Med. 2007 May 21; [Epub ahead of print].

Update Date: 12/12/2008

Updated by: A.D.A.M. Editorial Team: David Zieve, MD, MHA, Greg Juhn, MTPW, David R. Eltz. Previously reviewed by Elizabeth H. Holt, MD, PhD, Assistant Professor of Medicine, Section of Endocrinology and Metabolism, Yale University. Review provided by VeriMed Healthcare Network (6/17/2008).

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