Diabetes
Diabetes - type 1; Diabetes - type 2; Diabetes - gestational; Type 1 diabetes; Type 2 diabetes; Gestational diabetes; Diabetes mellitus
Diabetes is a chronic disease in which the body cannot regulate the amount of sugar in the blood.
Causes
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 stored or used as fuel.
People with diabetes have high blood sugar because their body cannot move sugar from the blood into muscle and fat cells to be burned or stored for energy, and because their liver makes too much glucose and releases it into the blood. 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:
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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. This is because the pancreas cells that make insulin stop working. Daily injections of insulin are needed. The exact cause is unknown.
Type 1 diabetes
Type 1 diabetes is a lifelong (chronic) disease in which there is a high level of sugar (glucose) in the blood.
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Type 2 diabetes
is much more common. It most often occurs in adulthood, but because of high obesity rates, children and teens are now being diagnosed with this disease. Some people with type 2 diabetes do not know they have it. With type 2 diabetes, the body is resistant to insulin and doesn't use insulin as well as it should.
Type 2 diabetes
Type 2 diabetes is a lifelong (chronic) disease in which there is a high level of sugar (glucose) in the blood. Type 2 diabetes is the most common f...
- There are other causes of diabetes, and some people cannot be classified as type 1 or type 2.
Gestational diabetes is high blood sugar that develops at any time during pregnancy in a woman who does not have diabetes.
Gestational diabetes
Gestational diabetes is high blood sugar (diabetes) that starts or is first diagnosed during pregnancy.
If your parent, brother, or sister has diabetes, you may be more likely to develop the disease.
Symptoms
A high blood sugar level can cause several symptoms, including:
- Blurry vision
- Excess thirst
-
Fatigue
Fatigue
Fatigue is a feeling of weariness, tiredness, or lack of energy.
- Frequent urination
- Hunger
- 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. People may be very sick by the time they are diagnosed.
After many years, diabetes can lead to other serious problems. These problems are known as diabetes complications, and include:
-
Eye problems
, including trouble seeing (especially at night), light sensitivity, and blindness
Eye problems
Diabetes can harm the eyes. It can damage the small blood vessels in the retina, the back part of your eye. This condition is called diabetic retin...
- Sores and infections of the leg or foot, which if untreated, can lead to amputation of the leg or foot
-
Damage to nerves in the body
, causing pain, tingling, a loss of feeling, problems digesting food, and erectile dysfunction
Damage to nerves in the body
Nerve damage that occurs in people with diabetes is called diabetic neuropathy. This condition is a complication of diabetes.
-
Kidney problems
, which can lead to
kidney failure
Kidney problems
Kidney disease or kidney damage often occurs over time in people with diabetes. This type of kidney disease is called diabetic nephropathy.
Kidney failure
Chronic kidney disease is the slow loss of kidney function over time. The main job of the kidneys is to remove wastes and excess water from the body...
- Weakened immune system, which can lead to more frequent infections
-
Increased chance of having a
heart attack
or
stroke
Heart attack
Most heart attacks are caused by a blood clot that blocks one of the coronary arteries. The coronary arteries bring blood and oxygen to the heart. ...
Stroke
A stroke occurs when blood flow to a part of the brain stops. A stroke is sometimes called a "brain attack. " If blood flow is cut off for longer th...
Exams and Tests
A urine analysis may show high blood sugar. But a urine test alone does not diagnose diabetes.
Urine analysis
Urinalysis is the physical, chemical, and microscopic examination of urine. It involves a number of tests to detect and measure various compounds th...
Your health care provider may suspect that you have diabetes if your blood sugar level is higher than 200 mg/dL (11.1 mmol/L). To confirm the diagnosis, one or more of the following tests must be done.
Blood tests:
-
Fasting blood glucose level
. Diabetes is diagnosed if the fasting glucose level is higher than 126 mg/dL (7.0 mmol/L) on two different tests. Levels between 100 and 126 mg/dL (5.5 and 7.0 mmol/L) are called impaired fasting glucose or prediabetes. These levels are risk factors for type 2 diabetes.
Fasting blood glucose level
A blood glucose test measures the amount of a sugar called glucose in a sample of your blood. Glucose is a major source of energy for most cells of t...
-
Hemoglobin A1c
(A1C) test. Normal is less than 5.7%; prediabetes is 5.7% to 6.4%; and diabetes is 6.5% or higher.
Hemoglobin A1c
A1C is a lab test that shows the average level of blood sugar (glucose) over the previous 3 months. It shows how well you are controlling your diabe...
-
Oral glucose tolerance test
. Diabetes is diagnosed if the glucose level is higher than 200 mg/dL (11.1 mmol/L) 2 hours after drinking a sugar drink (this test is used more often for type 2 diabetes).
Oral glucose tolerance test
The glucose tolerance test is a lab test to check how your body breaks down sugar. Tests to screen for diabetes during pregnancy are done differentl...
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 3 years
- Overweight adults (BMI of 25 or higher) who have other risk factors
- Adults over age 45, repeated every 3 years
Treatment
Type 2 diabetes may be reversed with lifestyle changes, especially losing weight with exercise and by eating healthier foods. Some cases of type 2 diabetes can also be improved with weight loss surgery.
There is no cure for type 1 diabetes.
Treating either type 1 diabetes or type 2 diabetes involves medicines, diet, and exercise to control blood sugar level.
Type 1 diabetes
Type 1 diabetes is a lifelong (chronic) disease in which there is a high level of sugar (glucose) in the blood.
Type 2 diabetes
Type 2 diabetes is a lifelong (chronic) disease in which there is a high level of sugar (glucose) in the blood. Type 2 diabetes is the most common f...
Everyone with diabetes should receive proper education and support about the best ways to manage their diabetes. Ask your provider about seeing a diabetes nurse educator.
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 provider at least 2 to 4 times a year. Talk about any problems you are having. Follow your provider's instructions on managing your diabetes.
Support Groups
Many resources can help you understand more about diabetes. If you have diabetes, you can also learn ways to manage your condition and prevent diabetes complications.
Resources
The following sites provide further information on diabetes:American Diabetes Association -- www. diabetes. orgJuvenile Diabetes Research Foundation ...
Outlook (Prognosis)
Diabetes is a lifelong disease and there is no cure.
Tight control of blood glucose can prevent or delay diabetes complications. But these problems can occur, even in people with good diabetes control.
Possible Complications
After many years, diabetes can lead to serious health problems:
- You could have eye problems, including trouble seeing (especially at night), and light sensitivity. You could become blind.
- Your feet and skin can develop sores and infections. After a long time, your foot or leg may need to be amputated. Infection can also cause pain and itching in other parts of the body.
- Diabetes may make it harder to control your blood pressure and cholesterol. This can lead to a heart attack, stroke, and other problems. It can become harder for blood to flow to your legs and feet.
- Nerves in your body can get damaged, causing pain, tingling, and numbness.
- Because of nerve damage, you could have problems digesting the food you eat. You could feel weakness or have trouble going to the bathroom. Nerve damage can make it harder for men to have an erection.
- High blood sugar and other problems can lead to kidney damage. Your kidneys may not work as well as they used to. They may even stop working so that you need dialysis or a kidney transplant.
Prevention
Keeping an ideal body weight and an active lifestyle may prevent or delay the start of type 2 diabetes. Some medicines can also be used to delay or prevent the start of type 2 diabetes.
At this time, type 1 diabetes cannot be prevented. But there is promising research that shows type 1 diabetes may be delayed in some high risk people.
References
Polonsky KS, Burant CF. Type 2 diabetes mellitus. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology . 13th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 31.
Standards of medical care in diabetes-2016: summary of revisions. Diabetes Care . 2016:39 Suppl 1:S4-S5. PMID 26696680 www.ncbi.nlm.nih.gov/pubmed/26696680 .
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Diabetes
Animation
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Diabetes treatment
Animation
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Type 2 Diabetes foot care
Animation
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Endocrine glands - illustration
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).
Endocrine glands
illustration
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Diabetic retinopathy - illustration
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.
Diabetic retinopathy
illustration
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Islets of Langerhans - illustration
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.
Islets of Langerhans
illustration
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Pancreas - illustration
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.
Pancreas
illustration
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Insulin pump - illustration
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.
Insulin pump
illustration
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Type I diabetes - illustration
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.
Type I diabetes
illustration
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Diabetic blood circulation in foot - illustration
People with diabetes are at risk for blood vessel injury, which may be severe enough to cause tissue damage in the legs and feet.
Diabetic blood circulation in foot
illustration
-
Food and insulin release - illustration
Insulin is a hormone secreted by the pancreas in response to increased glucose levels in the blood.
Food and insulin release
illustration
-
Insulin production and diabetes - illustration
Insulin is a hormone produced by the pancreas that is necessary for cells to be able to use blood sugar.
Insulin production and diabetes
illustration
-
Monitoring blood glucose - Series
Presentation
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Necrobiosis lipoidica diabeticorum - abdomen - illustration
Necrobiosis lipoidica diabeticorum is a chronic skin disease characterized by shiny plaques that vary in color from light yellowish to reddish-tan. It is seen more commonly in women. Although the name implies diabetes and the majority of cases occur in diabetics, this condition can occur in individuals without diabetes.
Necrobiosis lipoidica diabeticorum - abdomen
illustration
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Necrobiosis lipoidica diabeticorum - leg - illustration
Necrobiosis lipoidica diabeticorum is a chronic skin disease characterized by shiny plaques that vary in color from light yellowish to reddish-tan. It is seen more commonly in women. Although the name implies diabetes and the majority of cases occur in diabetics, this condition can occur in individuals without diabetes.
Necrobiosis lipoidica diabeticorum - leg
illustration
-
Endocrine glands - illustration
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).
Endocrine glands
illustration
-
Diabetic retinopathy - illustration
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.
Diabetic retinopathy
illustration
-
Islets of Langerhans - illustration
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.
Islets of Langerhans
illustration
-
Pancreas - illustration
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.
Pancreas
illustration
-
Insulin pump - illustration
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.
Insulin pump
illustration
-
Type I diabetes - illustration
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.
Type I diabetes
illustration
-
Diabetic blood circulation in foot - illustration
People with diabetes are at risk for blood vessel injury, which may be severe enough to cause tissue damage in the legs and feet.
Diabetic blood circulation in foot
illustration
-
Food and insulin release - illustration
Insulin is a hormone secreted by the pancreas in response to increased glucose levels in the blood.
Food and insulin release
illustration
-
Insulin production and diabetes - illustration
Insulin is a hormone produced by the pancreas that is necessary for cells to be able to use blood sugar.
Insulin production and diabetes
illustration
-
Monitoring blood glucose - Series
Presentation
-
Necrobiosis lipoidica diabeticorum - abdomen - illustration
Necrobiosis lipoidica diabeticorum is a chronic skin disease characterized by shiny plaques that vary in color from light yellowish to reddish-tan. It is seen more commonly in women. Although the name implies diabetes and the majority of cases occur in diabetics, this condition can occur in individuals without diabetes.
Necrobiosis lipoidica diabeticorum - abdomen
illustration
-
Necrobiosis lipoidica diabeticorum - leg - illustration
Necrobiosis lipoidica diabeticorum is a chronic skin disease characterized by shiny plaques that vary in color from light yellowish to reddish-tan. It is seen more commonly in women. Although the name implies diabetes and the majority of cases occur in diabetics, this condition can occur in individuals without diabetes.
Necrobiosis lipoidica diabeticorum - leg
illustration
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Diabetes
(Alt. Medicine)
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Diabetes diet
(In-Depth)
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Diabetes - type 1
(In-Depth)
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Diabetes - type 2
(In-Depth)
Review Date: 7/24/2015
Reviewed By: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine, Seattle, WA. Internal review and update on 09/01/2016 by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.