Type 1 diabetes Health Article

Definition

Type 1 diabetes is a chronic (lifelong) disease that occurs when the pancreas does not produce enough insulin to properly control blood sugar levels.

See also:

• Diabetes
• Gestational diabetes
• Type 2 diabetes

Alternative Names

Insulin-dependent diabetes; Juvenile onset diabetes; Diabetes - type 1

Causes, incidence, and risk factors

Diabetes is a lifelong disease for which there is not yet a cure. There are several forms of diabetes. Type 1 diabetes is often called juvenile or insulin-dependent diabetes. In this type of diabetes, cells of the pancreas produce little or no insulin, the hormone that allows sugar (glucose) to enter body cells.

Without enough insulin, glucose builds up in the bloodstream instead of going into the cells. The body is unable to use this glucose for energy despite high levels in the bloodstream. This leads to increased hunger.

In addition, the high levels of glucose in the blood causes increased urination. This leads to excessive thirst. Within 5 - 10 years, the insulin-producing beta cells of the pancreas are completely destroyed and the body can not longer produce insulin.

Type 1 diabetes can occur at any age. Many patients, however, are diagnosed after age 20.

The exact cause is unknown. Genetics, viruses, and autoimmune problems may play a role.

Symptoms

Possible symptoms include:

• Abdominal pain
• Absence of menstruation
• Fatigue
• Increased thirst
• Increased urination
• Nausea
• Vomiting
• Weight loss despite increased appetite

Signs and tests

Diabetes is diagnosed with the following blood tests:

• Fasting blood glucose level -- diabetes is diagnosed if it is higher than 126 mg/dL on two occasions
• Random (nonfasting) blood glucose level -- diabetes is suspected if it is higher than 200 mg/dL, and the patient has symptoms such as increased thirst, urination, and fatigue (this must be confirmed with a fasting test)
• Oral glucose tolerance test -- diabetes is diagnosed if the glucose level is higher than 200 mg/dL after 2 hours.

Ketone testing is also used in type 1 diabetes. Ketones are produced by the breakdown of fat and muscle. They are harmful at high levels. The ketone test is done using a urine sample. Ketone testing is usually done at the following times:

• When the blood sugar is higher than 240 mg/dL
• During an illness such as pneumonia, heart attack, or stroke
• When nausea or vomiting occur
• During pregnancy

People with diabetes should have their A1c (HbA1c) levels checked every 3 - 6 months. The HbA1c is a measure of average blood glucose during the past 2 - 3 months. It can help determine how well treatment is working.