The Facts
Diabetes (more specifically, diabetes mellitus) is a condition where people don't produce enough insulin to meet their body's needs, or their cells don't respond properly to insulin. Insulin is important because it moves glucose, a simple sugar, into the body's cells from the blood. It also has a number of other effects on metabolism.
The food people eat provides the body with glucose, which is used by the cells as a source of energy. If insulin isn't available or doesn't work correctly to move glucose from the blood into cells, glucose will stay in the blood. High blood glucose levels are toxic and cells that don't get glucose are lacking the fuel they need. These 2 problems cause the symptoms of diabetes.
There are 2 main kinds of diabetes: type 1 diabetes and type 2 diabetes. More than 90% of all people with diabetes have type 2 and fewer than 10% have type 1. Overall, about 20 million people in North America have diabetes. Only about two-thirds of people with type 2 diabetes are aware of it and are receiving treatment because, for many people, early symptoms are not noticeable without testing.
Type 1 diabetes used to be called juvenile diabetes, since it usually occurs in people under 30. Everyone with type 1 diabetes requires insulin injections. Type 1 diabetes occurs most commonly in people of northern European ancestry.
Type 2 diabetes used to be called adult-onset diabetes, because it usually occurs in people over 40. People with type 2 diabetes usually have a family history of this condition and are most often overweight. People with type 2 diabetes may eventually need insulin injections. This condition occurs most commonly in American Indians, Hispanics, and North Americans of African descent.
Another less common form is gestational diabetes, a temporary condition that occurs in 2% to 4% of pregnancies. The problem usually clears up after delivery, but women who have had gestational diabetes have a higher risk of developing type 2 diabetes later in life.