Type 1 diabetes mellitus, more commonly known as type 1 diabetes, is a disease in which the pancreas produces too little insulin to meet the body's needs. Insulin is a hormone that helps control the level of glucose in the blood. Glucose is the main form of sugar in the body.

What is going on in the body?

Glucose is a key source of energy for the cells of the body. When a person eats, the pancreas makes extra insulin to move glucose from the bloodstream to the inside of the cells, where it is converted to energy. A person with type 1 diabetes does not make enough insulin to move the glucose into the cells. As a result, the amount of glucose in the blood becomes too high. This condition is called hyperglycemia, and it can cause damage to the body, if left untreated.

What are the causes and risks of the disease?

The underlying cause of type 1 diabetes is damage to the pancreas caused by the person's own antibodies. It's not known why this occurs in some people and not others. Experts believe that it may be caused by an autoimmune disorder. An autoimmune disorder occurs when the body's immune system produces antibodies against the person's own tissues. In a person with type 1 diabetes, the antibodies attack the pancreas. The pancreas is a long, thin organ located behind the stomach. As a result, the pancreas can no longer make enough insulin to meet the body's needs.

Type 1 diabetes accounts for only 5% to 10% of cases of diabetes mellitus diagnosed in the United States. Type 2 diabetes, in which the body cells are resistant to insulin, is much more common.

Experts believe that people with type 1 diabetes have a genetic predisposition to the disease. Then, a trigger activates the disease at some point. Suspected triggers include viruses, environmental factors, and toxins.

Type 1 diabetes is rare in most Asian, African, and American Indian populations but more common in Caucasians. It is also more common in children and in adults younger than 30 years old, but it can appear at any age. It is most often diagnosed in young, thin individuals.