What Is Type 2 Diabetes?

There are two major types of diabetes: type 1 and type 2. Each type causes high blood sugar levels in a different way.
In type 1 diabetes, the pancreas can't make insulin. The body can still get glucose from food, but the glucose can't get into the cells, where it's needed, and glucose stays in the blood. This makes the blood sugar level very high.
With type 2 diabetes, a person's body still produces insulin. But a person with type 2 diabetes doesn't respond normally to the insulin the body makes. So glucose is less able to enter the cells and do its job of supplying energy.
When glucose can't enter the cells in this way, doctors call it insulin resistance. Although there's plenty of insulin in the person's body, because it doesn't work properly, the pancreas still detects high blood sugar levels. This makes the pancreas produce even more insulin.
The pancreas may eventually wear out from working overtime to produce extra insulin. When this happens, it may no longer be able to produce enough insulin to keep a person's blood sugar levels where they should be. In general, when someone's blood sugar levels are repeatedly high, it's a sign that he or she has diabetes.
Sometimes people with type 2 diabetes take pills that help the insulin in their bodies work better. Some people with type 2 diabetes also need insulin shots or an insulin pump to control their diabetes.