Type 1 diabetes is when the body does not make enough insulin. Insulin is a hormone that helps your body convert food into energy. Without insulin, glucose (sugar) from the food you eat cannot enter cells. So glucose builds up in the blood. Your body tissue becomes starved for energy.

Type 1 diabetes usually begins in children and young adults. Over the long-term, if type 1 diabetes is not adequately treated, high blood sugar levels can damage the blood vessels, heart, kidneys, eyes, nerves, and other tissues or organs.


Most cases of type 1 diabetes are caused by the body's immune system attacking and destroying the islet cells that make insulin. These cells are in the pancreas. The current theory is that some people have genes that make them prone to getting type 1 diabetes. For these people, certain things in the environment may trigger an immune system attack on the pancreas. The trigger or triggers have yet to be identified, but may be certain viruses, foods, or chemicals.

Some studies suggest that an enterovirus infection—which is common and usually causes diarrhea]]> and fever with or without rash—may contribute to the development of diabetes in some children. Children with relatively high birth weights are more likely to get diabetes than are those with lower weights.

How Type 1 Diabetes Occurs

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Risk Factors

These factors increase your chance of developing type 1 diabetes. Tell your doctor if you have any of these risk factors:

  • Family history (parent, sibling) of type 1 diabetes
  • Age: starts at age 4 with peak at ages 11-13
  • Sex: more common in males than females
  • Ethnicity: Northern European, Mediterranean, African Americans, Hispanics
  • Bottle-feeding or short duration of breastfeeding
  • Risk increases with increase in birth weight
  • Other autoimmune illness, including:



If you have any of these symptoms, do not assume it is due to type 1 diabetes. These symptoms may be caused by other conditions. Tell your doctor if you have any of these:

  • Weight loss
  • Increased urination
  • Extreme thirst
  • Hunger
  • Fatigue, weakness
  • Blurry vision
  • Irritability
  • Headaches

Destruction of insulin-producing pancreatic cells may occur so quickly that ketoacidosis]]> (commonly known as diabetic coma) is the first sign of a problem. Symptoms of ketoacidosis include:

  • Vomiting and nausea
  • Abdominal pain
  • ]]>Dehydration]]> (not enough fluid in the body)
  • Drowsiness
  • Abnormally deep and fast breathing
  • ]]>Coma]]>
  • Dry skin and mouth
  • Fruity breath odor
  • Rapid pulse
  • Low blood pressure



The doctor will ask about your symptoms, medical history, and family history, and do a physical exam.

Type 1 diabetes is diagnosed based on the results of blood tests and other criteria. These include:

  • Symptoms consistent with diabetes and a random blood test revealing a blood sugar level greater than or equal to 200 mg/dL* (11.1 mmol/L)
  • Blood sugar tests after you have not eaten for eight or more hours (called fasting blood test) revealing blood sugar levels greater than or equal to 126 mg/dL (7.0 mmol/L) on two different days
  • Glucose tolerance test measuring blood sugar two hours after you consume glucose with a measurement greater than or equal to 200 mg/dL (11.1 mmol/L)
  • HbA1c level of 6.5% or higher, indicating high blood sugar over the past 2-4 months

*mg/dL = milligrams per deciliter of blood, mmol/L = millimole per liter of blood

Some children may be tested for insulin levels or anti-pancreas antibodies to confirm the diagnosis.


Diabetes treatment aims to maintain blood sugar at levels as close to normal as possible. Regular medical care is important for preventing or delaying complications.


]]>]]>Insulin]]> injection replaces the natural insulin the pancreas would normally produce. The dosage is adjusted based on results of blood sugar tests before meals and at bedtime. You will need to have insulin shots two, three, or more times daily. Or you may wear an insulin pump that continually gives you a small amount of insulin. The pump connects to tubing and a small needle or catheter under the skin.


Amylin is made in the pancreas like insulin. In people with type 1 diabetes, this hormone is lacking, also like insulin. Researchers think that the post-meal glucose rise in people with ]]>type 2]]> diabetes is somehow related to the amylin deficiency. The drug ]]>pramlintide (Symlin)]]> may be used when insulin therapy is insufficient to adequately control blood sugar.


If you have type 1 diabetes, you should meet regularly with a registered dietician. Generally speaking, it is best to:

  • Follow a well-balanced meal plan incorporating a variety of food groups.
  • Eat consistently at regular times each day, including a bedtime snack.
  • Limit the amount of fat in the diet.
  • Avoid highly refined carbohydrates (sugar or high fructose products).


Exercise is encouraged when blood sugar levels are consistently under control and there are no complications. Follow your doctor's advice on activity levels and restrictions. You may need to adjust your insulin regimen or diet to compensate for low glucose levels linked to exercise.

Blood Sugar Testing

Checking blood sugar levels during the day helps you track the amount of glucose in your blood. Testing is easy with a blood glucose monitor. You can also ask your doctor about continuous glucose monitoring systems that you wear all day.

Keep a record of the results to show your doctor. Your treatment plan may change based on your test results. The HbA1c blood test is also used by your doctor to access your overall diabetes control.

Pancreatic Transplant

This procedure is recommended if you have:

  • Severe kidney disease and need a ]]>kidney transplant]]> at the same time as the ]]>pancreatic transplant]]>
  • Acute diabetic complications or emergencies not preventable by insulin
  • Severe problems due to injecting large amounts of insulin
  • Severe and frequent diabetic complications

If you are diagnosed with type 1 diabetes, follow your doctor's instructions .


Currently, there is no known way to prevent type 1 diabetes. Researchers are studying immunosuppressive treatments that may benefit high-risk people.