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What is Type 1 Diabetes?

Type 1 diabetes, which used to be called insulin-dependent or juvenile diabetes, is a chronic disease that destroys the body’s ability to make insulin, a hormone used to break down and store energy (in the form of glucose or “sugar”) from foods. Without insulin, high levels of fat and glucose remain in the bloodstream, which can damage blood vessels and vital organs over time.

Scientists do not know exactly what causes type 1 diabetes, but they believe that a combination of genetic and environmental factors are to blame. Diabetes is an autoimmune disease. This means that the immune system, which normally ignores healthy cells but destroys germs and foreign substances that could cause illness, mistakenly launches an attack on the body itself – in this case destroying insulin producing islet cells in the pancreas. People may develop type 1 diabetes at any age, but it is frequently diagnosed before adulthood. It accounts for about 5%-10% of all diabetes cases, and affects approximately one in every 400 to 500 children in the U.S.

Most Commonly Used Terms

Autoimmune disease: disorder of the body’s immune system in which the immune system mistakenly attacks and destroys body tissue considered foreign.

Islet cells: cells that make insulin and are found within the pancreas; also called pancreatic beta cells.

Islet transplantation: moving the islets from a donor pancreas into a person whose pancreas has stopped producing insulin. Beta cells in the islets make the insulin that the body needs for using blood glucose.

Pancreas: an organ that makes insulin and enzymes for digestion. The pancreas is located behind the lower part of the stomach and is about the size of a hand.

Insulin: A hormone made by the islet cells of the pancreas. Insulin controls the amount of sugar in the blood by moving it into the cells, where it can be used for energy.

Blood glucose: the main sugar that the body makes from food and the body’s main source of energy; cells cannot use glucose without the help of insulin. Also called blood sugar.

Clinical trials: Carefully controlled studies conducted to test the effectiveness and safety of new drugs, medical products or techniques. All drugs in the U.S. undergo three phases of clinical trials before being approved for general use.

Health services: services performed by health care professionals or by others under their direction for the purpose of promoting, maintaining, or restoring health.

Page last updated: September 24, 2019