What Is Diabetes?

Diabetes is a disease that affects how the body uses glucose, the main type of sugar in the blood. Glucose comes from the foods we eat and is the major source of energy needed to fuel the body's functions.

After you eat a meal, your body breaks down the foods you eat into glucose and other nutrients, which are then absorbed into the bloodstream from the gastrointestinal tract. The glucose level in the blood rises after a meal and triggers the pancreas to make the hormone insulin and release it into the bloodstream. But in people with diabetes, the body either can't make or respond to insulin properly.

Insulin works like a key that opens the doors to cells and allows the glucose in. Without insulin, glucose can't get into the cells (the doors are "locked" and there is no key) and so it stays in the bloodstream. As a result, the level of sugar in the blood remains higher than normal. High blood sugar levels are a problem because they can cause a number of symptoms and health problems.

What Is Type 2 Diabetes?

There are two major types of diabetes: type 1 and type 2. Both type 1 and type 2 diabetes cause blood sugar levels to become higher than normal. However, they cause high blood sugar levels to occur in different ways.

Type 1 diabetes (formerly called insulin-dependent diabetes or juvenile diabetes) occurs when the person's own immune system attacks and destroys the cells of the pancreas that produce insulin. Children with type 1 diabetes need insulin to help keep their blood sugar levels within a normal range.

Type 2 diabetes (formerly called non-insulin-dependent diabetes) is different. In contrast to someone with type 1 diabetes, someone with type 2 diabetes still produces insulin. But the body doesn't respond to the insulin normally. Glucose is less able to enter the cells and do its job of supplying energy (doctors call this insulin resistance). This causes the blood sugar level to rise, making the pancreas produce even more insulin. Eventually, the pancreas can wear out from working overtime to produce extra insulin. Then, the pancreas may no longer be able to produce enough insulin to keep a person's blood sugar levels within a normal range.

People with insulin resistance may or may not develop type 2 diabetes — it all depends on whether the pancreas can produce enough insulin to keep blood sugar levels normal. Repeatedly high blood sugar levels are a sign that a person has developed diabetes.

Children and teens with type 2 diabetes use diet, exercise, and medicines that improve the body's response to insulin to control their blood sugar levels. Sometimes kids and teens with type 2 diabetes may need to take insulin shots or use an insulin pump, too.