1 of 15 12/30/2012 10:52 PM PubMed Health. A service of the National Library of Medicine, National Institutes of Health. A.D.A.M. Medical Encyclopedia. Atlanta (GA): A.D.A.M.; 2011. Diabetes Last reviewed: June 27, 2012. Diabetes is usually a lifelong (chronic) disease in which there are high levels of sugar in the blood. Causes, incidence, and risk factors 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: A sugar called glucose enters the bloodstream. Glucose is a source of fuel for the body. An organ called the pancreas makes insulin. The role of insulin is to move glucose from the bloodstream into muscle, fat, and liver cells, where it can be used as fuel. 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: Their pancreas does not make enough insulin Their cells do not respond to insulin normally Both of the above There are two major types of diabetes. The causes and risk factors are different for each type: Type 1 diabetes can occur at any age, but it is most often diagnosed in children, teens, or young adults. In this disease, the body makes little or no insulin. Daily injections of insulin are needed. The exact cause is unknown. Type 2 diabetes makes up most diabetes cases. It most often occurs in adulthood. However, because of high obesity rates, teens and young adults are now being diagnosed with it. Many people with type 2 diabetes do not know they have it. 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). Symptoms High blood sugar levels can cause several symptoms, including: Blurry vision Excess thirst Fatigue Hunger Urinating often Weight loss 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:
2 of 15 12/30/2012 10:52 PM You could have eye problems, including trouble seeing (especially at night) and light sensitivity. You could become blind. Your feet and skin can get painful sores and infections. Sometimes, your foot or leg may need to be removed. Nerves in the body can become damaged, causing pain, tingling, and a loss of feeling. Because of nerve damage, you could have problems digesting the food you eat. This can cause trouble going to the bathroom. Nerve damage can also make it harder for men to have an erection. Signs 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: Fasting blood glucose level -- diabetes is diagnosed if it is higher than 126 mg/dl twice. Levels between 100 and 126 mg/dl are called impaired fasting glucose or pre-diabetes. These levels are risk factors for type 2 diabetes. Hemoglobin A1c test -- Normal: Less than 5.7% Pre-diabetes: 5.7% - 6.4% Diabetes: 6.5% or higher Oral glucose tolerance test -- diabetes is diagnosed if glucose level is higher than 200 mg/dl after 2 hours of drinking a glucose drink. (This test is used more often for type 2 diabetes.) Screening for type 2 diabetes in people who have no symptoms is recommended for: Overweight children who have other risk factors for diabetes, starting at age 10 and repeated every 2 years Overweight adults (BMI greater than 25) who have other risk factors Adults over age 45, repeated every 3 years Treatment 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. Treatming 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 Prevention Keeping an ideal body weight and an active lifestyle may prevent type 2 diabetes. There is no way yet to prevent type 1 diabetes. References
3 of 15 12/30/2012 10:52 PM 1. Alemzadeh R, Ali O. Diabetes Mellitus. In: Kliegman RM, ed. Kliegman: Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Saunders;2011:chap 583. 2. American Diabetes Association. Standards of medical care in diabetes -- 2012. Diabetes Care. 2012; 35 Suppl 1:S11-S63. 3. 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. 4. 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. 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.
4 of 15 12/30/2012 10:52 PM Figures Endocrine glands Endocrine glands release hormones (chemical messengers) into the bloodstream to be transported to various organs and tissues throughout the body. For instance, the pancreas secretes insulin, which allows the body to regulate levels of sugar in the blood. The thyroid gets instructions from the pituitary to secrete hormones which determine the pace of chemical activity in the body (the more hormone in the bloodstream, the faster the chemical activity; the less hormone, the slower the activity). Review Date: 7/19/2012. 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.
5 of 15 12/30/2012 10:52 PM Diabetic retinopathy Diabetes causes an excessive amount of glucose to remain in the blood stream which may cause damage to the blood vessels. Within the eye the damaged vessels may leak blood and fluid into the surrounding tissues and cause vision problems. 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.
6 of 15 12/30/2012 10:52 PM Islets of Langerhans Islets of Langerhans contain beta cells and are located within the pancreas. Beta cells produce insulin which is needed to metabolize glucose within the body. 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.
7 of 15 12/30/2012 10:52 PM Blood test To monitor the amount of glucose within the blood a person with diabetes should test their blood regularly. The procedure is quite simple and can often be done at home. 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.
8 of 15 12/30/2012 10:52 PM Pancreas The pancreas is located behind the liver and is where the hormone insulin is produced. Insulin is used by the body to store and utilize glucose. Review Date: 8/8/2012. Reviewed by: A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, and David R. Eltz. Previously reviewed by Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Redmond, Washington; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine (9/12/2011).
9 of 15 12/30/2012 10:52 PM Insulin pump Various styles of insulin pumps may be utilized by people with diabetes to inject insulin into the body in a controlled, more convenient and discreet manner. 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.
10 of 15 12/30/2012 10:52 PM Glucose test A person with diabetes constantly manages their blood's sugar (glucose) levels. After a blood sample is taken and tested, it is determined whether the glucose levels are low or high. If glucose levels are too low carbohydrates are ingested. If glucose in the blood is too high, the appropriate amount of insulin is administered into the body such as through an insulin pump. 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.
11 of 15 12/30/2012 10:52 PM Insulin pump The catheter at the end of the insulin pump is inserted through a needle into the abdominal fat of a person with diabetes. Dosage instructions are entered into the pump's small computer and the appropriate amount of insulin is then injected into the body in a calculated, controlled manner. 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.
12 of 15 12/30/2012 10:52 PM Type I diabetes In response to high levels of glucose in the blood, the insulin-producing cells in the pancreas secrete the hormone insulin. Type I diabetes occurs when these cells are destroyed by the body s own immune system. 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.
13 of 15 12/30/2012 10:52 PM Diabetic blood circulation in foot People with diabetes are at risk for blood vessel injury, which may be severe enough to cause tissue damage in the legs and feet. 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.
14 of 15 12/30/2012 10:52 PM Food and insulin release Insulin is a hormone secreted by the pancreas in response to increased glucose levels in the blood. 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.
15 of 15 12/30/2012 10:52 PM Insulin production and diabetes Insulin is a hormone produced by the pancreas that is necessary for cells to be able to use blood sugar. 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. A.D.A.M., Disclaimer Copyright 2012, A.D.A.M., Inc.