About Diabetes
Diabetes is a disease in which the body does not produce or properly use insulin. Insulin is a hormone that is needed to convert sugar, starches and other food into energy needed for daily life. The cause of diabetes continues to be a mystery, although both genetics and environmental factors such as obesity and lack of exercise appear to play roles.
There are 23.6 million children and adults in the United States, or 7.8% of the population, who have diabetes. While an estimated 17.9 million have been diagnosed with diabetes, unfortunately, 5.7 million people (or nearly one quarter) are unaware that they have the disease.
In order to determine whether or not a patient has pre-diabetes or diabetes, health care providers conduct a Fasting Plasma Glucose Test (FPG) or an Oral Glucose Tolerance Test (OGTT). Either test can be used to diagnose pre-diabetes or diabetes.
The major types of diabetes include: Type 1, Type 2, Gestational and pre-diabetes. More.
(source: American Diabetes Association)

Type 1 diabetes
Type 1 diabetes is usually diagnosed in children and young adults, and was previously known as juvenile diabetes. In type 1 diabetes, the body does not produce insulin. Insulin is a hormone that is needed to convert sugar (glucose), starches and other food into energy needed for daily life. Type 1 diabetes is serious, but people with diabetes can live long, healthy, happy lives. More.
(source: American Diabetes Association)

Type 2 diabetes
Type 2 diabetes is the most common form of diabetes. In type 2 diabetes, either the body does not produce enough insulin or the cells ignore the insulin. Insulin is necessary for the body to be able to use glucose for energy. When you eat food, the body breaks down all of the sugars and starches into glucose, which is the basic fuel for the cells in the body. Insulin takes the sugar from the blood into the cells. When glucose builds up in the blood instead of going into cells, it can cause two problems:

• Right away, your cells may be starved for energy.
• Over time, high blood glucose levels may hurt your eyes, kidneys, nerves or heart.
  

While diabetes occurs in people of all ages and races, some groups have a higher risk for developing type 2 diabetes than others. Type 2 diabetes is more common in African Americans, Latinos, Native Americans, and Asian Americans/Pacific Islanders, as well as the aged population. More.
(source: American Diabetes Association)

Gestational Diabetes
Pregnant women who have never had diabetes before but who have high blood sugar (glucose) levels during pregnancy are said to have gestational diabetes. Gestational diabetes affects about 4% of all pregnant women - about 135,000 cases of gestational diabetes in the United States each year.
Health professionals don't know what causes gestational diabetes, but there are some clues. The placenta supports the baby as it grows. Hormones from the placenta help the baby develop. But these hormones also block the action of the mother's insulin in her body. This problem is called insulin resistance. Insulin resistance makes it hard for the mother's body to use insulin. She may need up to three times as much insulin.
Gestational diabetes starts when your body is not able to make and use all the insulin it needs for pregnancy. Without enough insulin, glucose cannot leave the blood and be changed to energy. Glucose builds up in the blood to high level which leads to hyperglycemia. More.
(source: American Diabetes Association)

Pre-Diabetes
Before people develop type 2 diabetes, they almost always have "pre-diabetes" -- blood glucose levels that are higher than normal but not yet high enough to be diagnosed as diabetes. There are 57 million people in the United States who have pre-diabetes. Recent research has shown that some long-term damage to the body, especially the heart and circulatory system, may already be occurring during pre-diabetes.
Research has also shown that if you take action to manage your blood glucose when you have pre-diabetes, you can delay or prevent type 2 diabetes from ever developing. Together with the National Institute of Diabetes and Digestive and Kidney Diseases, the American Diabetes Association published a Position Statement on "The Prevention or Delay of Type 2 Diabetes" to help guide health care professionals in treating their patients with pre-diabetes.
There is much you can do to know your risks for pre-diabetes and to take action to prevent diabetes if you have, or are at risk for, pre-diabetes. The American Diabetes Association has a wealth of resources for people with diabetes. People with pre-diabetes can expect to benefit from much of the same advice for good nutrition and physical activity. More.
(source: American Diabetes Association)