Type 1 Diabetes

Type 1 diabetes, once known as juvenile diabetes or insulin-dependent diabetes, is a chronic condition in which the pancreas produces little or no insulin, a hormone needed to allow sugar (glucose) to enter cells to produce energy. The far more common type 2 diabetes occurs when the body becomes resistant to insulin or doesn't make enough insulin.

Various factors may contribute to type 1 diabetes, including genetics and exposure to certain viruses. Although type 1 diabetes usually appears during childhood or adolescence, it also can begin in adults.

Despite active research, type 1 diabetes has no cure. But it can be managed. With proper treatment, people with type 1 diabetes can expect to live longer, healthier lives than did people with type 1 diabetes in the past.

Symptoms

Type 1 diabetes signs and symptoms can come on quickly and may include:

Increased thirst
Frequent urination
Bedwetting in children who previously didn't wet the bed during the night
Extreme hunger
Unintended weight loss
Irritability and other mood changes
Fatigue and weakness
Blurred vision
In females, a vaginal yeast infection

When to see a doctor

Consult your doctor if you notice any of the above signs and symptoms in you or your child.

Causes

The exact cause of type 1 diabetes is unknown. In most people with type 1 diabetes, the body's own immune system — which normally fights harmful bacteria and viruses — mistakenly destroys the insulin-producing (islet) cells in the pancreas. Genetics may play a role in this process, and exposure to certain environmental factors, such as viruses, may trigger the disease.

The role of insulin

Once a significant number of islet cells are destroyed, you'll produce little or no insulin. Insulin is a hormone that comes from the pancreas, a gland situated behind and below the stomach.

The pancreas secretes insulin into the bloodstream.
Insulin circulates, enabling sugar to enter your cells.
Insulin lowers the amount of sugar in your bloodstream.
As your blood sugar level drops, so does the secretion of insulin from your pancreas.

The role of glucose

Glucose — a sugar — is a main source of energy for the cells that make up muscles and other tissues.

Glucose comes from two major sources: food and your liver.
Sugar is absorbed into the bloodstream, where it enters cells with the help of insulin.
Your liver stores glucose as glycogen.
When your glucose levels are low, such as when you haven't eaten in a while, the liver converts stored glycogen into glucose to keep your glucose level within a normal range.

In type 1 diabetes, there's no insulin to let glucose into the cells, so sugar builds up in your bloodstream, where it can cause life-threatening complications.