After school, when her friends flock to the store to pig out on candy and snack cakes, Sara passes up the sugary treats and sticks to the bottled water and half of a sandwich she packs. Her friends don't tease her, though, because they know that Sara has diabetes. Watching what she eats, getting plenty of exercise, and taking special medicine helps Sara live a normal, healthy life.

What Is Diabetes?

Diabetes is a disease that affects how the body uses glucose (pronounced: gloo-kose), a sugar that is the body's main source of fuel. Like your cell phone needs a battery, your body needs glucose to keep running. Here's how it should work.

1. You eat.
2. Glucose from the food enters your bloodstream.
3. Your pancreas makes a hormone called insulin (pronounced: in-suh-lin).
4. Insulin helps the glucose get into the body's cells.
5. Your body gets the energy it needs.

The pancreas is a long, flat gland in your belly that helps your body digest food. It also makes insulin. Insulin is kind of like a key that opens the doors to the cells of the body. It lets the glucose in. Then the glucose can move out of the blood and into the cells.

But if someone has diabetes, the body either can't make insulin or the insulin doesn't work in the body like it should. The glucose can't get into the cells normally, so the blood sugar level gets too high. Lots of sugar in the blood makes people sick if they don't get treatment.

What Is Type 1 Diabetes?

There are two major types of diabetes: type 1 and type 2. Each type causes high blood sugar levels in a different way.

In type 1 diabetes (which used to be called insulin-dependent diabetes or juvenile diabetes), the pancreas can't make insulin. That's because — for reasons doctors don't completely understand — the body's immune system attacked the pancreas and destroyed the cells that make insulin.

When a person has type 1 diabetes, the body is still able to get glucose from food, but the lack of insulin means that glucose can't get into the cells where it's needed. So the glucose stays in the blood. This makes the blood sugar level very high and causes health problems.

Once a person has type 1 diabetes, the pancreas can't ever make insulin again. To fix this problem, someone who has type 1 diabetes needs to take insulin through regular shots or an insulin pump.

Type 2 diabetes is different from type 1 diabetes. In type 2 diabetes, the pancreas still makes insulin. But the insulin doesn't work in the body like it should and blood sugar levels get too high.

What Causes Type 1 Diabetes?

No one knows for sure what causes type 1 diabetes, but scientists think it has something to do with genes. Genes are like instructions for how the body should look and work that are passed on by parents to their kids.

But just getting the genes for diabetes isn't usually enough. In most cases, something else has to happen — like getting a viral infection — for a person to develop type 1 diabetes.

Type 1 diabetes can't be prevented. Doctors can't even tell who will get it and who won't.

How Do People Know if They Have It?

People can have diabetes without knowing it because the symptoms aren't always obvious and they can take a long time to develop. Type 1 diabetes may come on gradually or suddenly.

When a person first has type 1 diabetes, he or she may:

• pee a lot because the body tries to get rid of the extra blood sugar by passing it out of the body in the urine
• drink a lot to make up for all that peeing
• eat a lot because the body is hungry for the energy it can't get from sugar
• lose weight because the body starts to use fat and muscle for fuel
• feel tired all the time

Also, girls who have developed diabetes are more likely to get vaginal yeast infections before they're diagnosed and treated.

If these early symptoms of diabetes aren't recognized and treatment isn't started, chemicals can build up in the blood and cause stomach pain, nausea, vomiting, breathing problems, and even loss of consciousness. Doctors call this diabetic ketoacidosis, or DKA.

There's good news, though — getting treatment can control or stop these diabetes symptoms from happening and reduce the risk of long-term problems.

Doctors can say for sure if a person has diabetes by testing blood samples for glucose. If the doctor suspects that a kid or teen has diabetes, he or she may send the person to see a pediatric endocrinologist — a doctor who specializes in diagnosing and treating children and teens living with diseases of the endocrine system, such as diabetes and growth problems.

Living With Type 1 Diabetes

People with type 1 diabetes have to pay a little more attention to what they're eating and doing than people who don't have diabetes.

They need to:

• check blood sugar levels a few times a day by testing a small blood sample
• give themselves insulin injections or use an insulin pump
• eat a balanced, healthy diet and pay special attention to the amounts of sugars and starches in the food they eat and the timing of their meals
• get regular exercise to help control blood sugar levels and help avoid some of the long-term health problems that diabetes can cause, like heart disease
• have regular checkups with doctors and other people on their diabetes health care team so they can stay healthy and get treatment for any diabetes problems

Sometimes people who have diabetes feel different from their friends because they need to take insulin, think about how they eat, and control their blood sugar levels every day.

Some teens with diabetes want to deny that they even have it. They might hope that if they ignore diabetes, it will just go away. They may feel angry, depressed, helpless, or that their parents are constantly in their faces about their diabetes management.

If you've been diagnosed with diabetes, it's normal to feel like your world has been turned upside down. Fortunately, your doctor or diabetes care team is there to provide answers and support. Don't hesitate to ask your doctors, dietitian, and other health professionals for advice and tips.

Also seek out support groups where you can talk about your feelings and find out how other people cope with the disease.

Diabetes brings challenges, of course. But teens with diabetes play sports, travel, date, go to school, and work just like their friends. There are thousands of teens with diabetes, all learning to handle the same challenges.

Reviewed by: Steven Dowshen, MD
Date reviewed: April 2012