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Diabetes, Type 1

Diabetes, Type 1

Animation Movie Available Related Media: The Importance of Healthy Eating When You Have Diabetes


Diabetes is a higher level of glucose in the blood than is normal. Glucose travels through the body in the blood. A hormone called insulin then helps glucose move from the blood to the cells. Once glucose is in the cells it can be used for energy. A problem making or using insulin means glucose cannot move into cells. Insulin also helps glucose to move into the liver for storage if there is too much to use. Without enough insulin, glucose will build up in the blood.

In type 1 diabetes, the body does not make insulin. This will lead to the build up of glucose in the blood, also called hyperglycemia. At the same time, cells are not getting glucose they need to function well. Over a long period of time high blood glucose levels can also damage vital organs. The blood vessels, heart, kidneys, eyes, and nerves are most commonly affected organs.

Type 1 diabetes is often found during childhood and young adulthood.


Our immune system keeps us well by fighting off and destroying viruses and bacteria. Unfortunately, sometimes the immune system attacks healthy tissue. Most type 1 diabetes develop because the immune system attacks and destroys the cells that make insulin. These cells are in the pancreas.

It is not yet clear why the immune system attacks these cells. It is believed that some people have genes that make them prone to getting diabetes. For these people, certain triggers in the environment may make the immune system attack the pancreas. The triggers are not known but may be certain viruses, foods, or chemicals.

Type 1 diabetes may also develop as a complication of other medical conditions. It may develop in:

  • People with chronic type 2 diabetes who lose the ability to make insulin.
  • Some with chronic pancreatitis or pancreatic surgery. They may lose the cells that make insulin.
The Pancreas
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Risk Factors

Type 1 diabetes is more common in males. It can start at any age but most commonly children and adolescents. Other factors that may increase your chance of type 1 diabetes include:

  • Family history of type 1 diabetes
  • Certain ethnic groups, such as Northern European, Mediterranean, African American, or Hispanic
  • Increased age of mother during pregnancy
  • Risk increases with increase in birth weight
  • Obesity during childhood
  • Other autoimmune disorders, including:
    • Hashimoto’s disease
    • Graves’ disease
    • Addison’s disease
    • Pernicious anemia
    • Celiac disease
    • Vitiligo
  • Cystic fibrosis


Type 1 diabetes may cause:

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

Without insulin, the body will need to find new forms of energy. This will cause an imbalance in the body called ketoacidosis. It is a severe state that can lead to coma or death. Ketoacidosis may cause:

  • Dry skin and mouth
  • Dehydration
  • Rapid pulse
  • Low blood pressure
  • Fruity breath odor
  • Vomiting and nausea
  • Abdominal pain
  • Drowsiness
  • Abnormally deep and fast breathing
  • Coma


You will be asked about your symptoms and medical history. A physical exam will be done.

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

  • Symptoms common with diabetes and a random blood test showing a blood sugar level greater than or equal to 200 mg/dL* (11.1 mmol/L)
  • Fasting blood test showing blood glucose levels greater than or equal to 126 mg/dL (7.0 mmol/L) on two different days—test is done after you have not eaten for eight or more hours
  • Glucose tolerance test results with blood glucose greater than or equal to 200 mg/dL (11.1 mmol/L)—test is done after you eat glucose
  • HbA1c level of 6.5% or higher—measure of blood sugar over the past 2-4 months

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

You may also need blood tests to confirm diabetes is type 1 and not type 2. These may include:

  • Insulin level or C-peptide tests—to see how much insulin is being made by the pancreas
  • Tests that look for antibodies that are working against your pancreas

You may also need other blood tests, including.

  • Cholesterol levels
  • Tests for autoimmune diseases, such as celiac disease and thyroid disease
  • Liver tests in adults


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

While diabetes makes blood glucose levels too high, treatment can make blood glucose levels go too low. This is called hypoglycemia. It can cause confusion, shakiness, anxiety, heart palpitations and more. If the levels fall too low it can cause seizures and loss of consciousness.

Medication and diet will be adjusted to prevent hyperglycemia and keep the risk of hypoglycemia low.


Over a long period of time, high blood glucose levels can damage vital organs. The risk of complications increases with increasingly poor control


There are no current guidelines to prevent type 1 diabetes.

Some research is looking at the effectiveness of suppressing the immune system. This may be helpful in people who are at high risk of developing type 1 diabetes.


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