Type 1 diabetes is a lifelong disease that develops when the pancreas stops producing insulin, a hormone that lets sugar (glucose) move from the blood into the body's cells, where it can be used for energy or stored for later use. If sugar cannot move from the blood into the cells, the person's blood sugar rises above a safe level and the cells cannot function properly.

Type 1 diabetes can develop at any age, although it typically develops in children and young adults, usually before the age of 30. Because of this, type 1 diabetes used to be called juvenile diabetes. It has also been called insulin-dependent diabetes mellitus (IDDM) because insulin injections must be taken daily.

Symptoms of type 1 diabetes usually develop quickly, over a few hours or a few days. Often symptoms are first noticed after an illness, such as the flu. Early warning signs of diabetes that are often overlooked include:

• Frequent urination.
• Extreme thirst.
• Increased hunger (possibly).
• Weight loss.

As blood sugar levels increase, more noticeable symptoms may develop, including blurred vision; drowsiness; fast and shallow breathing; a strong, fruity breath odor; loss of appetite; abdominal pain; and vomiting.

Treatment for type 1 diabetes focuses on keeping the person's blood sugar level as close to normal as possible. This is done by eating a balanced diet, taking insulin injections, and getting regular exercise.