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Type 1 Diabetes



Type 1 diabetes is a disease that starts when the pancreas stops making insulin. Insulin lets blood sugar—also called glucose—enter the body's cells to be used for energy. Without insulin, the cells can't get the sugar they need, and too much sugar builds up in the blood.

Diabetes can cause sudden or long-term problems. If the body doesn't have enough insulin and the blood sugar gets very high, a sudden and very serious problem called diabetic ketoacidosis can happen. This can be deadly. Over time, high blood sugar can damage the eyes, heart, blood vessels, nerves, and kidneys.

Type 1 diabetes can occur at any age, but it usually starts in children or young adults. That’s why it used to be called juvenile diabetes.

Type 1 diabetes is different from type 2 diabetes, which is the most common form of the illness. In type 1, the body stops making insulin. In type 2, the body does not make enough insulin, or the body can't use insulin the right way. All people with type 1 diabetes need to take insulin. Some people with type 2 diabetes also need insulin, but most people can use diet, exercise, and medicine in pills to treat that illness.

There isn't a cure for type 1 diabetes. But with treatment, people can live long and healthy lives.

There is no way to prevent type 1 diabetes. But studies are being done to find ways to prevent or delay diabetes in people who are most likely to get it.

Tight control of blood sugar and blood pressure can help people with type 1 diabetes prevent or delay problems with their eyes, kidneys, heart, blood vessels, and nerves.


The body makes insulin in beta cells, which are in a part of the pancreas called the islet (say “EYE-let”) tissue. Type 1 diabetes starts because the body destroys the beta cells. Experts don't know why this happens.

Some people have a greater chance of getting type 1 diabetes, because they have a parent, brother, or sister who has it. But most people with the illness don't have a family history of it.

Other things that increase the risk of getting type 1 diabetes are being white and having islet cell antibodies in the blood.


Risk factors

Risk factors for type 1 diabetes include:


Symptoms of type 1 diabetes usually develop quickly, over a few days to weeks, and are caused by blood sugar levels rising above the normal range (hyperglycemia). Early symptoms may be overlooked, especially if the person has recently had an illness, such as influenza (flu). Early symptoms include:

Sometimes the blood sugar level rises excessively before a person knows something is wrong. Because insulin is not available, the cells in the body are unable to get the sugar (glucose) they need for energy. The body begins to break down fat and muscle for energy. When fat is used for energy, ketones—or fatty acids—are produced and enter the bloodstream, causing the chemical imbalance diabetic ketoacidosis. This is a life-threatening condition. Symptoms of diabetic ketoacidosis are:


A doctor asks questions about the person’s health and does a physical exam. A blood test measures the person’s glucose.

Sometimes people notice diabetes symptoms after an illness, such as the flu. If they do not seek medical care quickly, the lack of insulin can cause the blood sugar level to rise much higher than normal. The body then uses fat and muscle for energy, which causes the release of ketones, or fatty acids. Ketones can lead to a chemical imbalance called diabetic ketoacidosis. It is a medical emergency. Symptoms of diabetic ketoacidosis include confusion; strong, fruity breath; and drowsiness, or even coma.

Sometimes after receiving initial treatment for type 1 diabetes, people have a period of time—from a few weeks to a few months—when the pancreas is again able to produce insulin. This is often called the "honeymoon period." At this time, a person may need to take little or no insulin, depending on how much insulin the pancreas produces. When the honeymoon period is over, the person needs to take insulin for the rest of his or her life.



Many people are not diagnosed with type 1 diabetes until they are admitted to a hospital for diabetic ketoacidosis (DKA). This life-threatening condition occurs when ketones, or fatty acids, are produced as the body burns fat and muscle instead of glucose for fuel. DKA develops in people who have type 1 diabetes (and some people who have type 2 diabetes) when their blood sugar is very high.

During hospitalization, people with DKA will be watched closely and receive tests to measure the levels of electrolytes and sugar (glucose) in their blood.

If a person is not in ketoacidosis, a doctor uses blood sugar tests, the American Diabetes Association's criteria for symptoms, a medical history, and a physical examination to diagnose type 1 diabetes.

A blood glucose test is used to measure blood sugar. This test is done preferably after fasting, but it can be done at any time, even if you have recently eaten.

Other tests that may suggest diabetes

A hemoglobin A1c test is recommended for monitoring blood sugar control after treatment has begun because it estimates average blood sugar level over the previous 2 to 3 months. It may be done when a person is diagnosed, and it may be used as a comparison for blood sugar control after treatment starts.

You may need a thyroid-stimulating hormone (TSH) test when type 1 diabetes is diagnosed and then every 1 to 2 years. This test checks for thyroid problems, which are common among people with diabetes.

Neither a home blood sugar test nor a urine test for sugar is recommended to screen for or diagnose diabetes.

Treatment for adults

Type 1 diabetes requires lifelong treatment to keep blood sugar levels within a target range. Treatment includes:

A regular daily schedule makes managing blood sugar levels easier. Blood sugars are easier to predict and control when mealtimes, amounts of food, and exercise are similar every day.

Many people find out that they have type 1 diabetes when they are admitted to a hospital for diabetic ketoacidosis. If their symptoms are severe, they may need to be treated in an intensive care unit. Treatment for diabetic ketoacidosis includes fluids given through a vein (intravenous, or IV) to treat dehydration and to balance electrolytes, and insulin to lower the blood sugar level and stop the body from producing ketones.


Treatment for children

Treatment for children includes all of the above measures to keep blood sugar levels within the child's target range. Treatment for children should also allow for normal growth and development.

When a small child has diabetes, the parents have the responsibility for blood sugar control. As the child grows, he or she can take more responsibility for diabetes care.

Planning pregnancy when you have type 1 diabetes

Women who want to plan a pregnancy need to talk to their doctors about making sure they have good control of their blood sugar. Higher-than-normal blood sugar levels during the first trimester of pregnancy raise the risk of birth defects. Good preconception care of diabetes appears to reduce the risk of birth defects.

Women with diabetes who do not want to be become pregnant should use birth control. This reduces the risk of birth defects in unplanned pregnancies.


This infomation was taken from the University of Michigan Health System's Health Library.