Type 2 diabetes is a chronic disease. It is characterized by high levels of sugar in the blood. Type 2 diabetes is also called type 2 diabetes mellitus and adult-onset diabetes. However, more and more children and teens are developing this condition. Since type 2 diabetes is much more common than type 1 diabetes, it often is just called "diabetes".
During digestion, food is broken down into basic components. Carbohydrates are broken down into simple sugars, primarily glucose. Glucose is a critically important source of energy for the body's cells. To provide energy to the cells, glucose needs to leave the blood and get inside the cells.
Insulin traveling in the blood signals the cells to take up glucose. Insulin is a hormone produced by the pancreas. When levels of glucose in the blood rise (for example, after a meal), the pancreas produces more insulin.
Type 2 diabetes occurs when your body's cells do not react efficiently to insulin. This condition is called insulin resistance. The cells do not accept as much glucose from the blood as they should. The cells resist the effects of insulin. As a result, glucose starts to build up in the blood.
In people with insulin resistance, the pancreas "sees" the blood glucose level rising. The pancreas responds by making extra insulin to maintain a normal blood sugar. Over time, the body's insulin resistance gets worse. In response the pancreas makes more and more insulin. Finally, the pancreas gets "exhausted". It cannot keep up with the demand for more and more insulin. As a result, blood glucose levels stay high.
Type 2 diabetes runs in families. It most often affects people who are older than 40. But type 2 diabetes is now being seen in more and more young people. Obesity greatly increases the risk of diabetes.