A NIDDK Overview of Diabetes
Almost every one of us knows
someone who has diabetes. An estimated 16 million people in the United States
have diabetes mellitus -- a serious, lifelong condition. About half of these
people do not know they have diabetes and are not under care for the disorder.
Each year, about 798,000 people are diagnosed with diabetes.
Although diabetes occurs most often in older
adults, it is one of the most common chronic disorders in children in the
United States. About 123,000 children and teenagers age 19 and younger have
What Is Diabetes?
Diabetes is a disorder of metabolism -- the
way our bodies use digested food for growth and energy. Most of the food we eat
is broken down by the digestive juices into a simple sugar called glucose.
Glucose is the main source of fuel for the body.
After digestion, the glucose passes into our
bloodstream where it is available for body cells to use for growth and energy.
For the glucose to get into the cells, insulin must be present. Insulin is a
hormone produced by the pancreas, a large gland behind the stomach.
When we eat, the pancreas is supposed to
automatically produce the right amount of insulin to move the glucose from our
blood into our cells. In people with diabetes, however, the pancreas either
produces little or no insulin, or the body cells do not respond to the insulin
that is produced. As a result, glucose builds up in the blood, overflows into
the urine, and passes out of the body. Thus, the body loses its main source of
fuel even though the blood contains large amounts of glucose.
What Are the Different Types of Diabetes?
The three main types of diabetes
- Type 1 diabetes
- Type 2 diabetes
- Gestational diabetes
Type 1 Diabetes
Type 1 diabetes (once known as
insulin-dependent diabetes mellitus or juvenile diabetes) is considered an
autoimmune disease. An autoimmune disease results when the body's system for
fighting infection (the immune system) turns against a part of the body. In
diabetes, the immune system attacks the insulin-producing beta cells in the
pancreas and destroys them. The pancreas then produces little or no
Someone with type 1 diabetes needs daily
injections of insulin to live. At present, scientists do not know exactly what
causes the body's immune system to attack the beta cells, but they believe that
both genetic factors and viruses are involved. Type 1 diabetes accounts for
about 5 to 10 percent of diagnosed diabetes in the United States.
Type 1 diabetes develops most often in
children and young adults, but the disorder can appear at any age. Symptoms of
type 1 diabetes usually develop over a short period, although beta cell
destruction can begin years earlier.
Symptoms include increased thirst and
urination, constant hunger, weight loss, blurred vision, and extreme tiredness.
If not diagnosed and treated with insulin, a person can lapse into a