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Type 2 Diabetes Overview

Type 2 diabetes, often called non-insulin dependent diabetes, is the most common form of diabetes, affecting 90% - 95% of the 21 million people with diabetes. In this article, you'll learn the basics about type 2 diabetes, including symptoms and causes, as well as type 2 diabetes in children.

What Is Type 2 Diabetes?
Unlike people with type 1 diabetes, people with type 2 diabetes produce insulin; however, the insulin their pancreas secretes is either not enough or the body is unable to recognize the insulin and use it properly. This is called insulin-resistance. When there isn't enough insulin or the insulin is not used as it should be, glucose (sugar) can't get into the body's cells. When glucose builds up in the blood instead of going into cells, the body's cells are not able to function properly. Other problems associated with the buildup of glucose in the blood include:

Dehydration. The buildup of sugar in the blood can cause an increase in urination (to try to clear the sugar from the body). When the kidneys lose the glucose through the urine, a large amount of water is also lost, causing dehydration.
Diabetic Coma (Hyperosmolar nonketotic diabetic coma). When a person with type 2 diabetes becomes severely dehydrated and is not able to drink enough fluids to make up for the fluid losses, they may develop this life-threatening complication.

Damage to the body. Over time, the high glucose levels in the blood may damage the nerves and small blood vessels of the eyes, kidneys, and heart and predispose a person to atherosclerosis (hardening) of the large arteries that can cause heart attack and stroke.

What Causes Type 2 Diabetes?
Although it is more common than type 1 diabetes, the causes of type 2 diabetes are less well understood. It is likely caused by multiple factors and not a single problem.

Type 2 diabetes can run in families, but the exact nature of how it's inherited or the identity of a single genetic factor is not known.

For more detail, see WebMD's article Causes of Type 2 Diabetes.

What Are the Symptoms of Type 2 Diabetes?
The symptoms of type 2 diabetes vary from person to person but may include:

Increased thirst.
Increased hunger (especially after eating).
Dry mouth.
Nausea and occasionally vomiting.
Frequent urination.
Fatigue (weak, tired feeling).
Blurred vision.
Numbness or tingling of the hands or feet.
Frequent infections of the skin, urinary tract or vagina.

Rarely, a person may be diagnosed with type 2 diabetes after presenting to the hospital in a diabetic coma.

For more detail, see WebMD's article Type 2 Diabetes Symptoms.

How Is Type 2 Diabetes Diagnosed?
To diagnose type 2 diabetes, your health care provider will first check for abnormalities in your blood (high blood glucose level). In addition, he or she may look for glucose or ketone bodies in your urine.

Type 2 diabetes testing includes a fasting plasma glucose test or a casual plasma glucose test. You will also need to check your blood sugar levels regularly.

For more detail, see WebMD's article Diagnosis of Diabetes.

Complications Associated With Type 2 Diabetes
If your diabetes isn't well controlled, there are a number of serious or life-threatening problems you may experience, including:

Retinopathy. People with type 2 diabetes may already have abnormalities in the eyes related to the development of diabetes. Over time more and more people who initially do not have eye problems related to the disease will develop some form of eye problem. It is important to control not only sugars but blood pressure and cholesterol to prevent progression of eye disease. Fortunately, the vision loss isn't significant in most.

Kidney damage. The risk of kidney disease increases over time, meaning the longer you have diabetes the greater your risk. This complication carries significant risk of serious illness -- such as kidney failure and heart disease.

Poor blood circulation and nerve damage. Damage to nerves and hardening of the arteries leads to decreased sensation and poor blood circulation in the feet. This can lead to increased infections and an increased risk of ulcers which heal poorly and can in turn significantly raises the risk of amputation. Damage to nerves may also lead to digestive problems, such as nausea, vomiting and diarrhea.

For more detail, see WebMD's article Preventing Diabetes Complications.