Topic Overview
Is this topic for you?
This topic has general
information about
type 1 diabetes for people who do not have the
disease. If you want to learn how to manage type 1 diabetes, one of the
following topics may meet your needs:
- Type 1 Diabetes: Recently Diagnosed, if you have been
told recently that you or your child has type 1 diabetes.
- Type 1 Diabetes: Living With the Disease, if you or
your child age 12 or older has type 1 diabetes. If you have not read the topic
Type 1 Diabetes: Recently Diagnosed, you may want to read it
first.
- Type 1 Diabetes: Children Living With the Disease, if
your child age 11 or younger has type 1 diabetes. If you have not read the
topic Type 1 Diabetes: Recently Diagnosed, you may want to read it
first.
- Type 1 Diabetes: Living With Complications, if you have complications, such
as eye, kidney, heart, nerve, or blood vessel disease caused by
diabetes.
If you are looking for information about
type 2 diabetes, see the topic
Type 2 Diabetes.
What is 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.
What causes type 1 diabetes?
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.
What are the symptoms?
Symptoms of diabetes are:
- Being very thirsty.
- Urinating a
lot.
- Losing weight without trying.
- Being hungrier than
usual (sometimes).
These symptoms usually appear over a few days to weeks.
Sometimes people notice symptoms after an illness, such as the flu. They may
think that the diabetes symptoms are because of the flu, so they don't seek
medical care soon enough.
If a person waits too long to get
medical care, he or she may get symptoms of diabetic ketoacidosis. Symptoms of
this problem include:
- Flushed, hot, dry skin.
- Not
feeling hungry.
- Belly pain.
- Vomiting.
- A
strong, fruity breath odor.
- Fast and shallow
breathing.
- Restlessness, drowsiness, or trouble waking
up.
- Confusion.
How is type 1 diabetes diagnosed?
A doctor asks
questions about the person’s health and does a physical exam. A blood test
measures the person’s glucose.
Some people are diagnosed with type
1 diabetes because they have symptoms of diabetic ketoacidosis.
How is it treated?
Treatment for type 1 diabetes
focuses on keeping blood sugar levels as close to the normal range as possible.
A person with type 1 diabetes needs to:
- Take insulin through daily shots or an
insulin pump.
- Eat a healthy diet that spreads
carbohydrate throughout the day.
- Check
blood sugar levels several times a day.
- Get regular
exercise.
When a small child has diabetes, the parents have the
responsibility for blood sugar control. As the child grows, he or she can take
over more of the diabetes care.
Treatment may change based on the
results of daily home blood sugar tests and other tests or exams.
Can type 1 diabetes be prevented?
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.
Frequently Asked Questions
Learning about type 1 diabetes: | |
Being diagnosed: | |
Getting treatment: | |
Ongoing concerns: | |
Living with type 1 diabetes: | |
Cause
Type 1 diabetes develops because the
body's
immune system destroys the beta cells which are in the
islet tissue in the
pancreas. These beta cells produce insulin. So people
with type 1 diabetes cannot make their own insulin.
You can
inherit a tendency to develop type 1 diabetes, but most people who have the
disease have no family history of it. Diabetes experts believe that a genetic
tendency and some environmental factors may increase the risk of developing
type 1 diabetes. Possible environmental factors include
enteroviral infections—especially Coxsackie B
infections.
Despite concerns about vaccines (particularly those
against whooping cough and Haemophilus influenza B, or
Hib), studies have not found a relationship between being vaccinated and
developing type 1 diabetes.1
Symptoms
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:
- Frequent urination, which may be more
noticeable at night. Some young children who have learned to use the toilet may
start wetting the bed during naps or at night.
- Extreme thirst and a
dry mouth.
- Weight loss.
- Increased hunger
(possibly).
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:
- Flushed, hot, dry skin.
- Loss of
appetite, abdominal pain, and vomiting.
- A strong, fruity breath
odor.
- Rapid, deep breathing.
- Restlessness, drowsiness,
difficulty waking up, confusion, or coma. Young children may lack interest in
their normal activities.
What Happens
Type 1 diabetes
develops because the body destroys the beta cells in the islet tissue of the
pancreas that produce
insulin. The rate at which the beta cells are
destroyed varies. Infants and children usually develop the disease suddenly
because the beta cells are destroyed rapidly. Adults tend to develop the
disease slowly because the beta cells are destroyed gradually.
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.
Every person who has type 1 diabetes requires
treatment designed for his or her needs. Treatment involves:
People with type 1 diabetes often have blood sugar levels
outside of their
target range. These out-of-range levels happen because
injections of insulin cannot control blood sugar as smoothly as natural insulin
made by your body. Blood sugar below a normal range (hypoglycemia) can develop
quickly and lead to an emergency in only a few minutes. On the other hand, high
blood sugar levels (hyperglycemia) usually develop slowly over hours or days.
If blood sugar levels continue to rise, diabetic ketoacidosis can
develop.
Over time, diabetes can damage the body's tissues.
Persistent high blood sugar can damage the eyes (diabetic retinopathy), kidneys
(diabetic nephropathy), nerves (diabetic neuropathy), and heart (leading to
heart attacks). It also can damage blood vessels,
leading to
strokes and blockage of other arteries, especially in
the legs. People who keep their blood sugar levels as close to normal as
possible often can prevent—or at least delay—these complications. But some
people still develop complications even with good blood sugar control.
People who work closely with their doctors and follow their prescribed
treatment usually feel better and more in control of their lives.
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 care of diabetes before conception 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.
What Increases Your Risk
Risk factors for
type 1 diabetes include:
- Family history of type 1 diabetes. Having a family history of the disease increases the chance
that a person will have
islet cell antibodies, but it does not predict that a
person will have the disease. Only about 10% to 15% of people with type 1
diabetes have a family history of the disease.1
- If the father has the disease, a child has
a 6% risk of developing it.
- If a sibling has the disease, a child
has a 5% risk of developing it.
- If the mother has the disease, a
child has a 2% risk of developing it.
- If an identical twin has the
disease, the other twin has a 30% to 50% risk of developing it.
- If
a parent and one sibling have the disease, a child has a 30% risk of developing
it.
- Race. White people have a
greater risk for developing type 1 diabetes than black, Asian, or Hispanic
people.
- Presence of islet cell antibodies in the blood. People who have both a family history of type 1 diabetes and
islet cell antibodies in their blood are likely to develop the disease at some
time.
When To Call a Doctor
Call 911 or other emergency services immediately if you or your child is:
- Unconscious or becomes very sleepy
unexpectedly. You or your child may have low blood sugar, called
hypoglycemia. While waiting for emergency help,
follow:
- Drowsy, confused, breathing fast, and your or
your child’s breath smells fruity. You or your child may have high blood sugar,
called hyperglycemia. A life-threatening condition called
diabetic ketoacidosis could be present.
Call a doctor immediately if you or
your child is vomiting and cannot keep down liquids and:
- Your blood sugar is 300 mg/dL or
higher.
- Your child’s blood sugar is 250 mg/dL or higher.
Call a doctor if you or your child:
- Has increased urination, increased thirst,
weight loss, and possibly increased appetite. These symptoms may indicate
type 1 diabetes.
- Has a family history of
type 1 diabetes and wants to be tested.
Watchful Waiting
Watchful waiting is a period of time during
which you and your doctor observe your symptoms or condition without using
medical treatment. Watchful waiting is not appropriate if you think you or your
child may have symptoms of type 1 diabetes, such as increased urination,
increased thirst, weight loss, and possibly increased appetite. A blood test is
all that is needed to determine whether a person has the disease.
Who To See
The following health professionals can diagnose and
treat diabetes:
To prepare for your appointment, see the topic Making the Most of Your Appointment.
Exams and Tests
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.
Early Detection
Screening for type 1 diabetes is not recommended
by the American Diabetes Association. Such screening would include testing
everyone for
islet cell antibodies. This test can show if a person
is more likely to get type 1 diabetes.
People who are found to
have islet cell antibodies may be able to participate in studies about
preventing type 1 diabetes. These people need to be referred to a medical
center conducting a type 1 diabetes prevention study.2
Treatment Overview
Treatment for adults
Type 1 diabetes
requires lifelong treatment to keep blood sugar levels within a
target range. Treatment includes:
- Taking several
insulin injections every day or using an
insulin pump.
- Monitoring blood sugar
levels several times a day using a home blood sugar meter.
- Eating
a healthful diet that spreads
carbohydrate throughout the day, to prevent high blood
sugar levels after meals.
- Regular physical exercise, because exercise helps the body to use insulin more
efficiently. Exercise may also lower your risk for heart and blood vessel
disease.
- Regular medical checkups to monitor and adjust treatment
as needed. Screening tests and exams need to be done regularly to watch for
signs of complications, such as eye, kidney, heart, blood vessel, and nerve
diseases.
- Not smoking.
- Not drinking alcohol if the
person is at risk for periods of low blood sugar.
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.3
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. See the topics
Type 1 Diabetes: Recently Diagnosed and
Type 1 Diabetes: Children Living With the Disease.
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.
Prevention
Preventing type 1 diabetes
Currently there is no
way to prevent
type 1 diabetes, but ongoing studies are exploring
ways to prevent diabetes in those who are most likely to develop it. People who
have a parent, brother, or sister with type 1 diabetes and are willing to
participate in one of these studies should talk with their doctors. They may
want to be tested for
islet cell antibodies, because if they have these
antibodies, they are more likely to get diabetes.
Vaccines have
not been found to contribute to the development of type 1 diabetes.4 Children who are at risk for developing diabetes still need
to get the recommended
immunizations. See the
childhood immunization schedule recommended by the
U.S. Advisory Committee on Immunization Practices, the American Academy of
Pediatrics, and the American Academy of Family Physicians.
Preventing diabetes complications
People with type
1 diabetes can help prevent or delay the development of complications such as
eye, kidney, heart, blood vessel, and nerve diseases by keeping their blood
sugar near normal levels. They also need regular medical checkups to detect
early signs of complications. If complications are treated early, the damage
may be stopped, slowed, or possibly reversed.
People who have
other health problems along with diabetes, such as
high blood pressure or
high cholesterol, need to treat those conditions.
Also,
not smoking can reduce the risk of complications. Having other health
problems can increase the risk for complications from diabetes.
Preventing flu and pneumococcal disease
People
who have diabetes should have a flu shot every year and a pneumococcal vaccine.
Usually, people need only one dose of the pneumococcal vaccine. But doctors
sometimes recommend a second dose for some people, especially if they have a
long-term disease. Talk with your doctor about whether you need a second dose.
The pneumococcal vaccine helps prevent infections caused by pneumococcal
bacteria. People with diabetes, especially those who have heart or kidney
disease, are at high risk for complications, hospitalization, and death from
flu and pneumococcal disease.5
Home Treatment
People who have
type 1 diabetes need to work closely with their
doctors to find the right balance of diet, insulin, and exercise to keep their
blood sugar levels within a
target range. That combination will vary over time,
especially for children.
Daily treatment for diabetes
includes:
Other steps to take
People with type 1 diabetes
also need to:
- Wear
medical identification at all times so that, in case of emergency, health
professionals can see that they have diabetes.
- Treat high and low blood sugar levels quickly to prevent an
emergency.
- Take extra care of their feet, gums, and teeth to
prevent problems that may develop because of high blood sugar.
- Know
how to adjust their diet or insulin doses
when they are sick or when they become pregnant.
- Have regular medical checkups to monitor the disease and adjust
treatment as needed.
Medications
A person who has
type 1 diabetes must take
insulin every day because his or her
pancreas does not produce it. Insulin helps blood
sugar (glucose) enter the body's cells to be used for energy. Insulin can be
given as an injection into the fatty tissue under the skin or through an
insulin pump.
Usually people with type 1
diabetes take a combination of types of insulin, such as a long-acting insulin
once or twice a day and a rapid-acting insulin before each meal. The amount and
type of insulin needed varies for each person. Also, the amount and type of
insulin needed changes over time, depending on age, hormones (such as during
rapid growth or pregnancy), and changes in exercise routine. In addition, a
person may need higher doses of insulin during times of illness or emotional
stress.
Other medicines may be needed if a person develops
complications from diabetes, such as kidney disease.
A person also
may need medicines to treat
high blood pressure or
high cholesterol and help prevent complications from
diabetes. If you are 40 or older, talk to your doctor about taking a low-dose
aspirin daily to help prevent
heart attack,
stroke, or other large blood vessel disease.
Surgery
Surgery for
type 1 diabetes is done only in special
situations.
- Surgery to replace the pancreas (pancreas
transplant) may be done when a person is receiving another organ, such as a
kidney.
- Surgery to insert working pancreas cells (islet cell
transplant) is experimental.
These surgeries are very expensive. After having one of
these surgeries, a person must take medicine for the rest of his or her life to
prevent the body from rejecting the new tissue (immunosuppression
medicines).
Other Treatment
People who have
type 1 diabetes need to avoid products that promise a
“cure.” No cure exists. They also need to avoid products for diabetes that are
advertised by testimonials without a sound medical basis. These products or
remedies may be harmful and costly. They also might cause people to delay or
avoid getting other forms of treatment that have been proved to work.
References
Citations
- Lawson ML, Muirhead SE (2001). What is type 1
diabetes? In HC Gerstein, RB Haynes, eds., Evidence-Based Diabetes Care, pp. 124–150. Hamilton, ON: BC
Decker.
- American Diabetes Association (2004). Prevention of
type 1 diabetes mellitus. Clinical Practice Recommendations 2004.
Diabetes Care, 27(Suppl 1): S133.
- American Diabetes Association (2004). Hyperglycemic
crises in diabetes. Clinical Practice Recommendations 2004. Diabetes Care, 27(Suppl 1): S94–S102.
- Hviid A, et al. (2008). Childhood vaccination and
type 1 diabetes. New England Journal of Medicine,
350(14): 1398–1404.
- American Diabetes Association (2004). Influenza and
pneumococcal immunization in diabetes. Clinical Practice Recommendations 2004.
Diabetes Care, 27(Suppl 1): S111–S113.
Other Works Consulted
- American Diabetes Association (2006). Pancreas and islet transplantation in type 1 diabetes. Position statement. Diabetes Care, 29(4): 935.
- Genuth S (2008). Type 1 diabetes mellitus. In DC Dale,
DD Federman, eds., ACP Medicine, section 9, chap. 1. New
York: WebMD.
- Pickup J, Keen H (2002). Continuous subcutaneous insulin infusion at 25 years. Diabetes Care, 25(30): 593–598.
- White SA, et al. (2001). Human islet cell
transplantation: Future prospects. Diabetic Medicine,
18(2): 78–103.
Credits
| Author | Caroline Rea, RN, BS, MS |
| Editor | Susan Van Houten, RN, BSN, MBA |
| Associate Editor | Pat Truman, MATC |
| Primary Medical Reviewer | Caroline S. Rhoads, MD - Internal Medicine |
| Specialist Medical Reviewer | Matthew I. Kim, MD - Endocrinology & Metabolism |
| Last Updated | September 17, 2008 |