Diabetes is usually a lifelong (chronic) disease in which there are high levels of sugar in the blood.


Insulin is a hormone produced by the pancreas to control blood sugar. Diabetes can be caused by too little insulin, resistance to insulin, or both.

To understand diabetes, it is important to first understand the normal process by which food is broken down and used by the body for energy. Several things happen when food is digested:

People with diabetes have high blood sugar because their body cannot move sugar into fat, liver, and muscle cells to be stored for energy. This is because either:

There are two major types of diabetes. The causes and risk factors are different for each type:

Gestational diabetes is high blood sugar that develops at any time during pregnancy in a woman who does not have diabetes.

Diabetes affects more than 20 million Americans. Over 40 million Americans have pre-diabetes (which often comes before type 2 diabetes).


High blood sugar levels can cause several symptoms, including:

Because type 2 diabetes develops slowly, some people with high blood sugar have no symptoms.

Symptoms of type 1 diabetes develop over a short period of time. People may be very sick by the time they are diagnosed.

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

Exams and Tests

A urine analysis may show high blood sugar. However, a urine test alone does not diagnose diabetes.

Your health care provider may suspect that you have diabetes if your blood sugar level is higher than 200 mg/dL. To confirm the diagnosis, one or more of the following tests must be done.

Blood tests:

Screening for type 2 diabetes in people who have no symptoms is recommended for:


Early on in type 2 diabetes, you may be able to reverse the disease with lifestyle changes. Also, some cases of type 2 diabetes can be cured with weight-loss surgery.

There is no cure for type 1 diabetes.

Treating both type 1 diabetes and type 2 diabetes involves medicines, diet, and exercise to control blood sugar levels and prevent symptoms and problems.

Getting better control over your blood sugar, cholesterol, and blood pressure levels helps reduce the risk of kidney disease, eye disease, nervous system disease, heart attack, and stroke.

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

Support Groups

For more information, see American Diabetes Association -- www.diabetes.org


Keeping an ideal body weight and an active lifestyle may prevent type 2 diabetes.

There is no way yet to prevent type 1 diabetes.


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 -- 2012. Diabetes Care. 2012; 35 Suppl 1:S11-S63.

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, a scientific statement of the American Heart Association, and an expert consensus document of the American College of Cardiology Foundation. Circulation. 2010;121:2694-2701.

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.

Review Date: 6/27/2012
Reviewed By: Shehzad Topiwala, MD, Chief Consultant Endocrinologist, Premier Medical Associates, The Villages, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.
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