Type 1 diabetes


Type 1 diabetes is a lifelong (chronic) disease in which there are high levels of sugar (glucose) in the blood.

See also:

Alternative Names

Insulin-dependent diabetes; Juvenile onset diabetes; Diabetes - type 1


Type 1 diabetes can occur at any age. However, it is most often diagnosed in children, adolescents, or young adults.

Insulin is a hormone produced by special cells, called beta cells, in the pancreas. The pancreas is found behind your stomach. Insulin is needed to move blood sugar (glucose) into cells, where it is stored and later used for energy. In type 1 diabetes, beta cells produce little or no insulin.

Without enough insulin, glucose builds up in the bloodstream instead of going into the cells. The body is unable to use this glucose for energy. This leads to the symptoms of type 1 diabetes.

The exact cause of type 1 diabetes is unknown. Most likely it is an autoimmune disorder. An infection or some other trigger causes the body to mistakenly attack the cells in the pancreas that make insulin. This kind of disorder can be passed down through families.


These symptoms may be the first signs of type 1 diabetes, or may occur when the blood sugar is high:

For other people, these warning symptoms may be the first signs of type 1 diabetes, or they may happen when the blood sugar is very high (see: diabetic ketoacidosis):

Low blood sugar (hypoglycemia) can develop quickly in people with diabetes who are taking insulin. Symptoms usually appear when the blood sugar level falls below 70 mg/dL. Watch for:

Exams and Tests

Diabetes is diagnosed with the following blood tests:

Ketone testing is also sometimes used. The ketone test is done using a urine sample or blood sample. Ketone testing may be done:

The following tests or exams will help you and your doctor monitor your diabetes and prevent problems caused by diabetes:


Because type 1 diabetes can start quickly and the symptoms can be severe, people who have just been diagnosed may need to stay in the hospital.

If you have just been diagnosed with type 1 diabetes, you should probably have a check-up each week until you have good control over your blood sugar. Your health care provider will review the results of your home blood sugar monitoring and urine testing. Your provider will also look at your diary of meals, snacks, and insulin injections.

As the disease gets more stable, you will have fewer follow-up visits. Visiting your health care provider is very important so you can monitor any long-term problems from diabetes.

You are the most important person in managing your diabetes. You should know the basic steps to diabetes management:


Insulin lowers blood sugar by allowing it to leave the bloodstream and enter cells. Everyone with type 1 diabetes must take insulin every day.

Insulin is usually injected under the skin. In some cases, a pump delivers the insulin all the time. Insulin does not come in pill form.

Insulin types differ in how fast they start to work and how long they last. The health care provider will choose the best type of insulin for you and will tell you at what time of day to use it. More than one type of insulin may be mixed together in an injection to get the best blood glucose control. You may need insulin shots from one to four times a day.

Your health care provider or diabetes nurse educator will teach you how to give insulin injections. At first, a child's injections may be given by a parent or other adult. By age 14, most children can give their own injections.

People with diabetes need to know how to adjust the amount of insulin they are taking:


People with type 1 diabetes should eat at about the same times each day and try to eat the same kinds of foods. This helps to prevent blood sugar from becoming too high or low. See also:

The American Diabetes Association and the American Dietetic Association have information for planning healthy, balanced meals. It can help to talk with a registered dietitian or nutrition counselor.

Regular exercise helps control the amount of sugar in the blood. It also helps burn extra calories and fat to reach a healthy weight.

Ask your health care provider before starting any exercise program. People with type 1 diabetes must take special steps before, during, and after intense physical activity or exercise. See also: Diabetes and exercise


Checking your blood sugar levels at home and writing down the results will tell you how well you are managing your diabetes. Talk to your doctor and diabetes educator about how often to check.

A device called a glucometer can read blood sugar levels. There are different types of devices. Usually, you prick your finger with a small needle called a lancet to get a tiny drop of blood. You place the blood on a test strip and put the strip into the device. You should have results in 30 - 45 seconds.

Keep a record of your blood sugar for yourself and your doctor or nurse. This will help if you have problems managing your diabetes. You and your doctor should set a target goal for your blood sugar levels at different times during the day. You should also plan what to do when your blood sugar is too low or high.

For more information, see: Managing your blood sugar

Low blood sugar is called hypoglycemia. Blood sugar levels below 70 mg/dL are too low and can harm you.


Diabetes damages the blood vessels and nerves. This can make you less able to feel pressure on the foot. You may not notice a foot injury until 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 or deeper.

To prevent problems with your feet:


Your doctor may prescribe medications or other treatments to reduce your chances of developing eye disease, kidney disease, and other conditions that are more common in people with diabetes.

See also:

Support Groups

For more information and resources, see diabetes support group.

Outlook (Prognosis)

Diabetes is a lifelong disease and there is not yet a cure. However, the outcome for people with diabetes varies.

Studies show that tight control of blood glucose can prevent or delay problems with the eyes, kidneys, nervous system, and heart in type 1 diabetes. However, problems may occur even in people with good diabetes control.

Possible Complications

If you have diabetes, your risk of a heart attack is the same as someone who has already had a heart attack. Both women and men with diabetes are at risk. You may not even have the normal signs of a heart attack.

After many years, diabetes can lead to other serious problems:

See also: Diabetic ketoacidosis

When to Contact a Medical Professional

Call 911 if you have:

Call your health care provider or go to the emergency room if you have symptoms of diabetic ketoacidosis.

Also call your doctor if you have:

You can treat early signs of hypoglycemia at home by eating sugar or candy, or by taking glucose tablets. If your signs of hypoglycemia continue or your blood glucose levels stay below 60 mg/dL, go to the emergency room.


There is no way to prevent type 1 diabetes. There is no screening test for type 1 diabetes in people who have no symptoms.

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


Alemzadeh R, Ali O. Diabetes Mellitus. In: Kliegman RM, ed. Kliegman: Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Saunders; 2011:chap 583.

American Diabetes Association. Standards of medical care in diabetes -- 2011. Diabetes Care. 2011. 34 Suppl 1:S11-S61.

Eisenbarth GS, Polonsky KS, Buse JB. Type 1 diabetes mellitus. In: Kronenberg HM, Melmed S, Polonsky KS, Larsen PR. Kronenberg: Williams Textbook of Endocrinology. 11th ed. Philadelphia, Pa: Saunders Elsevier;2008:chap 31.

Pignone M, Alberts MJ, Colwell JA, Cushman M, Inzucchi SE, Mukherjee D, et al. Aspirin for primary prevention of cardiovascular events in people with diabetes: a position statement of the American Diabetes Association, and an expert consensus document of the American College of Cardiology Foundation. Circulation. 2010. 121:2694-2701.

Review Date: 6/28/2011
Reviewed By: Ari S. Eckman, MD, Division of Endocrinology, Diabetes and Metabolism, Trinitas Regional Medical Center, Elizabeth, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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