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This topic covers type 1 diabetes, including information about symptoms, tests, and home treatment. For specific information about children who have type 1 diabetes, see the topic Type 1 Diabetes: Children Living With the Disease.
Type 1 diabetes happens when your pancreas stops making
Insulin is a hormone that helps the body's cells use sugar (glucose) for energy. It also helps the body store extra energy in muscle, fat, and liver cells. Without insulin, this sugar can't get into your cells to do its work. It stays in your blood instead. And then your blood sugar level gets too high.
High blood sugar can harm many parts of the body, such as the eyes, heart, blood vessels, nerves, and kidneys. It can also increase your risk for other health problems (complications).
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
Type 1 diabetes is different from type 2 diabetes. In type 1 diabetes, the body stops making
insulin. In type 2, the body doesn't make enough insulin, or the body can't
use insulin the right way.
There isn't a cure for type 1 diabetes. But with treatment, people can
live long and healthy lives.
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 those
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
Other things that increase the risk of
getting type 1 diabetes are being white and having
islet cell antibodies in the blood.
Symptoms of diabetes are:
These symptoms usually appear over a few days to weeks.
Sometimes people notice symptoms after an illness, like the flu. They may
think that the diabetes symptoms are because of the flu, so they don't seek
medical care soon enough.
If you wait too long to get
medical care, you may get diabetic ketoacidosis, which is very dangerous. Symptoms of
this problem include:
Your doctor can diagnose diabetes with a physical exam, your medical history, and blood tests.
Some people are diagnosed with type
1 diabetes because they have symptoms of diabetic ketoacidosis.
Treatment for type 1 diabetes
focuses on keeping blood sugar levels within a target range and doing things to reduce complications.
To control your blood sugar, you:
High blood sugar can lead to problems such as:
Learning about type 1 diabetes:
Living with type 1 diabetes:
Health Tools help you make wise health decisions or take action to improve your health.
Type 1 diabetes develops because the
immune system destroys beta cells in a part of the pancreas called the
islet tissue. These beta cells produce insulin. So people
with type 1 diabetes can't make their own insulin.
The pancreas normally adjusts
the amount of insulin it makes based on your changing blood sugar. When you have diabetes, your insulin
injections can't control your blood sugar moment to moment, the way your pancreas
would. So you may have high and low blood sugar levels from time to
Causes of high blood sugar include:
Sometimes a person's blood sugar level rises greatly before he or she knows something is wrong. Because insulin isn't 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. This causes the
diabetic ketoacidosis. This is a life-threatening
Causes of low blood sugar include:
type 1 diabetes usually develop quickly, over a few
days to weeks, and are caused by high blood sugar. At first, symptoms may be overlooked or mistaken for another illness, like the flu.
High blood sugar symptoms include:
See more about symptoms of high blood sugar.
Symptoms of diabetic ketoacidosis are:
Common symptoms of low blood sugar include:
can pass out when your blood sugar gets very low.
See more about symptoms of low blood sugar.
If you aren't able to tell when your blood sugar is too low (hypoglycemic unawareness), it's a good idea to test your blood sugar often.
It's not possible for injected insulin to work as well as a normal pancreas, so you will have high and low blood sugar levels from time to time.
If your blood sugar stays above your target range for a long time, it can damage many parts of your body.
High blood sugar levels can lead to vision loss and blindness (diabetic retinopathy).
To learn more, see the topic Diabetic Retinopathy.
Having diabetes also puts you at risk for cataracts or
You may have less feeling in your feet, which means that you can injure your feet and not know it. Common infections from blisters, ingrown toenails, small cuts, or other problems can quickly become more serious when you have diabetes.
If you get serious infections or bone and joint deformities, you may need surgery (even amputation) to treat those problems.
High blood sugar damages the lining of large blood vessels. This can lead to stroke, heart attack, or peripheral arterial disease.
High blood sugar levels can damage nerves throughout your body. This damage is called diabetic neuropathy.
There are three kinds of diabetic neuropathy:
To learn more, see the topic Diabetic Neuropathy.
The kidneys have many tiny blood vessels that filter waste from your blood. High blood sugar can destroy these blood vessels. You won't have any symptoms of kidney damage until the
problem is severe. Then you may notice swelling in your
feet or legs or all over your body.
To learn more, see the topic Diabetic Nephropathy.
High blood sugar can damage the small blood vessels and nerves in the ear, causing hearing loss.
Gum disease can make it harder to keep blood sugar in a target range. And high blood sugar can cause gum disease, loss of teeth, and healing problems in the mouth.
The stress of dealing with diabetes or the effects that diabetes has on your body can lead to depression.
Being depressed can make it hard to eat healthy foods and to find the motivation to exercise. All of these things lead to higher blood sugar.
By getting help for depression, you'll feel better and may find it easier to stay motivated.
Risk factors are things that increase your chances of getting sick or having a problem. Risk factors for
type 1 diabetes include:
Call 911 or other emergency services right away if:
Call a doctor if:
Check with your doctor if:
Health professionals who may be involved in your diabetes care include:
If you have signs of complications of diabetes, such as nerve problems or kidney problems, you may be referred to a specialist. Learn more about the roles of the health professionals on a diabetes care team.
Women who want to
plan a pregnancy need to talk to their doctors about
making sure they have good control of their blood sugar.
High 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 don't want to be
become pregnant should use birth control. This reduces the risk of birth
defects in unplanned pregnancies.
To prepare for your appointment, see the topic Making the Most of Your Appointment.
If your doctor thinks that you may have diabetes, he or she will order blood tests to measure how much sugar is in your blood. The tests used are:
Your doctor will use your blood test results and the American Diabetes Association (ADA) criteria to diagnose diabetes. He or she will also do a medical history and physical exam.
You'll need to see your doctor every 3 to 6 months. At your visits, your doctor may:
Regular visits and checkups with your doctor are also a good time to:
These visits are also a good time to talk with your doctor about how you're feeling. It's normal to feel frustrated or overwhelmed with all there is to do. If you're having trouble coping, your doctor can help.
After you have had type 1 diabetes for 3 to 5 years, your doctor may recommend these tests.
If you get
pregnant, you will need to have an
eye exam sometime during the
first 3 months. You'll also need close follow-up
during your pregnancy and for 1 year after you
have your baby. Pregnancy may increase your risk for diabetic retinopathy. If you already have eye disease and
get pregnant, the disease can quickly get
Type 1 diabetes
requires treatment to keep blood sugar levels within a
target range. Treatment includes:
Blood sugars are easier to predict and control when mealtimes,
amounts of food, and exercise are similar every day. So getting into a daily routine helps a lot.
Some people find out that they have type 1 diabetes when they are admitted to a hospital
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.
If your blood sugar levels return to the normal range soon after
diagnosis, you are in what is called the "honeymoon period."
This is a time
when the remaining insulin-producing cells in your
pancreas are working harder to supply enough insulin
for your body.
Treatment during this time may include:
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 get 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.
People who have type 1 diabetes can help prevent or delay the development of complications by keeping their blood sugar in a target range. 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.
When you have diabetes, you need a flu(What is a PDF document?) vaccine every year. You also need a hepatitis B (Hep B)(What is a PDF document?) vaccine.
You also need a pneumococcal shot. Your doctor can help you choose between the pneumococcal polysaccharide vaccine (Pneumovax)(What is a PDF document?) or the pneumococcal conjugate vaccine (Prevnar)(What is a PDF document?).
You may need or want additional immunizations if certain situations raise your chance for exposure to disease.
Type 1 diabetes
requires daily attention to diet, exercise, and insulin. You may have times
when this job feels overwhelming, but getting into a daily routine can help. And taking good care of yourself will also help
you feel better, have a better quality of life, and prevent or delay
complications from diabetes.
Carbohydrate is the one nutrient in your diet that
most affects blood sugar levels. A registered dietitian can help you learn
about what foods contain carbohydrate and how to manage it in your diet.
You need to take injections every
day, because your
pancreas no longer produces
insulin. To learn more, see Medications.
Your doctor will want
you to test your blood sugar level several times a day.
It's also important to know how to recognize and treat high or low blood sugar quickly.
Try to do
moderate activity at least 2½ hours a week.1 One way to do this is to be active 30 minutes a day, at least
5 days a week.
Exercise safely. Drink plenty of water
before, during, and after you are active. This is very important when it's hot out and when you do intense
exercise. You can also try keeping track of your exercise on an
activity log(What is a PDF document?).
Daily foot care can prevent
serious problems. Foot problems caused by diabetes are the most common cause of
In addition to exercising, it is a
good idea to limit the amount of alcohol you drink. The American Diabetes
Association recommends that women with diabetes have no more than 1 drink a
day and men with diabetes have no more than 2 drinks a day.2
One drink is
12 fl oz (0.4 L) of beer,
5 fl oz (0.2 L) of wine, or
1.5 fl oz (44.4 mL)
Having type 1 diabetes can cause a lot of
problems in your body. Smoking can make many of these problems worse,
especially heart and blood vessel disease.
Smoking raises your
cholesterol and makes it harder for your body to heal.
No matter how long you've smoked, your health will improve after you quit.
Insulin helps keep your blood sugar level tightly
controlled and within a target range. It can be taken by an injection or through an
Usually people who have 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.
The amount and type of
insulin you need changes over time, depending on age, hormones (such as during
rapid growth or pregnancy), and changes in exercise routine. You may need higher doses of insulin during times of illness or emotional
Learn about insulin:
You may also take an amylinomimetic, such as pramlintide (Symlin). This medicine is only used with insulin, but it's given in a separate shot.
If small amounts of protein are found when
your urine is tested, you may be in the early stage of
diabetic nephropathy. You may be given an
angiotensin-converting enzyme (ACE) inhibitor or an
angiotensin II receptor blocker (ARB).
Talk to your doctor about whether you should take low-dose aspirin. Daily low-dose aspirin (81 milligrams) may help prevent heart problems if you are at risk for heart attack or stroke.
You may need one or more medicines to lower blood pressure.
may need to take
medicine to lower your cholesterol.
Treating high blood pressure and high cholesterol may help prevent complications from
You may need other medicines if you develop complications, such as kidney disease.
Some complications from
type 1 diabetes are treated with surgery. For
example, surgery to remove the
vitreous gel (vitrectomy) may improve eye disease.
When insulin isn't enough to keep blood sugar in your target range, a pancreas transplant might be an option. If it's successful, you may no longer have symptoms or need to treat diabetes.
But you may still get complications from diabetes. If you already have complications, they may continue to get worse as time goes on.
The success rate for pancreas transplants is improving
because of new surgical techniques and new medicines.
If you get a transplanted pancreas, you must take medicine to keep your body from rejecting the new organ.
A pancreas transplant can be done at the same time as a kidney transplant.
Research continues on pancreatic islet cell surgery. It involves inserting a small group of donated pancreas cells (islet cells) through a vein in your liver. After surgery, these cells begin making insulin. If they can make enough, you may no longer need insulin injections.
Because the surgery is simpler than a pancreas transplant, there are usually fewer complications. But you must still take medicine to prevent rejection.
Avoid products that promise a "cure"
diabetes. For example, antioxidant supplements (vitamins E, C, and carotene) don't cure diabetes. The American Diabetes Association doesn't recommend taking them.2
If you hear about something new to help diabetes, do some research to find out if it really works. You can also check with your doctor or a
diabetes educator. Your health plan may also provide health information on its website.
therapies may help relieve stress and muscle tension. They might help you feel better in general. But
they shouldn't be used instead of treatment.
Talk with your doctor if you are using:
The American Diabetes Association (ADA) is a national organization
for health professionals and consumers. Almost every state has a local office.
ADA sets the standards for the care of people with diabetes. Its focus is on
research for the prevention and treatment of all types of diabetes. ADA
provides patient and professional education mainly through its publications,
which include the monthly magazine Diabetes Forecast,
books, brochures, cookbooks and meal planning guides, and pamphlets. ADA also
provides information for parents about caring for a child with diabetes.
The Juvenile Diabetes Research Foundation International is dedicated to finding a cure for type 1 diabetes and its complications. The organization funds research on type 1 diabetes, including research on prevention and treatment. This
organization publishes a wide variety of booklets, magazines, and e-newsletters on complications and
treatments of type 1 diabetes.
The National Diabetes Education Program (NDEP) is
sponsored by the U.S. National Institutes of Health (NIH) and the U.S. Centers
for Disease Control and Prevention (CDC). The program's goal is to improve the
treatment of people who have diabetes, to promote early diagnosis, and to
prevent the development of diabetes. Information about the program can be found
on two Web sites: one managed by NIH (http://ndep.nih.gov) and the other by CDC
This clearinghouse provides information about research
and clinical trials supported by the U.S. National Institutes of Health. This
service is provided by the National Institute of Diabetes and Digestive and
Kidney Disease (NIDDK), a part of the National Institutes of Health (NIH).
U.S. Department of Health and Human Services (2008). 2008 Physical Activity Guidelines for Americans (ODPHP Publication No. U0036). Washington, DC: U.S. Government Printing Office. Available online: http://www.health.gov/paguidelines/guidelines/default.aspx.
American Diabetes Association (2013). Standards of medical care in diabetes—2013. Diabetes Care, 36(Suppl 1): S11–S66.
Other Works Consulted
American Diabetes Association (2013). Standards of medical care in diabetes—2013. Diabetes Care, 36(Suppl 1): S11–S66.
Beaser RS (2010). Designing a conventional insulin treatment program. In RS Beaser, ed., Joslin's Diabetes Deskbook: A Guide for Primary Care Providers, 2nd ed., pp. 297–340. Boston: Joslin Diabetes Center.
Brownlee M, et al. (2011). Complications of diabetes mellitus. In S Melmed et al., eds., Williams Textbook of Endocrinology, 12th ed., pp. 1462–1551. Philadelphia: Saunders.
Campbell AP, Beaser RS (2010). Medical nutrition therapy. In RS Beaser, ed., Joslin's Diabetes Deskbook: A Guide for Primary Care Providers, 2nd ed., pp. 91–136. Boston: Joslin Diabetes Center.
Centers for Disease Control and Prevention (2011). National Diabetes Fact Sheet 2011. Available online: http://www.cdc.gov/diabetes/pubs/factsheet11.htm.
Eisenbarth GS, Buse JB (2011). Type 1 diabetes mellitus. In S Melmed et al., eds., Williams Textbook of Endocrinology, 12th ed., pp. 1436–1461. Philadelphia: Saunders.
Hunt DL (2011). Diabetes: Foot ulcers and amputations, search date September 2010. BMJ Clinical Evidence. Available online: http://www.clinicalevidence.com.
Masharani U, German MS (2011). Pancreatic hormones and diabetes mellitus. In DG Gardner, D Shoback, eds., Greenspan's Basic and Clinical Endocrinology, 9th ed., pp. 573–655. New York: McGraw-Hill.
Mohamed QA, et al. (2011). Diabetic retinopathy (treatment), search date June 2010. BMJ Clinical Evidence. Available online: http://www.clinicalevidence.com.
Nix S (2009). Diabetes mellitus. In William’s Basic Nutrition and Diet Therapy, 13th ed., pp. 383–410. St. Louis: Mosby Elsevier.
Vijan S (2012). Diabetes: Treating hypertension, search date April 2011. BMJ Clinical Evidence: Available online: http://www.clinicalevidence.com.
Wolfsdorf JI, Garvey K (2012). Type 1 diabetes mellitus. In EG Nabel, ed., ACP Medicine, section 9, chap. 1. Hamilton, ON: BC Decker.
September 11, 2012
Adam Husney, MD - Family Medicine & Matthew I. Kim, MD - Endocrinology
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