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Type 2 diabetes happens when your body can't use insulin the right way or when the pancreas can't make enough insulin.
Insulin is a hormone that helps the body's cells use sugar (glucose) for energy. It also helps the body store extra sugar 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. Your blood sugar level then 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 2 diabetes is different from type 1 diabetes. In type 1 diabetes, the body's immune system destroys the cells that release insulin, so that over time the body can't produce insulin at all. In type 2 diabetes, the body still makes some insulin, but it can't use it the right way.
You can get type 2 diabetes if:
If you are overweight, get little or no exercise, or have type 2 diabetes in your family, you are more likely to have problems with the way insulin works in your body. Type 2 diabetes can be prevented or delayed with a healthy lifestyle, including staying at a healthy weight, making healthy food choices, and getting regular exercise.
Some people don't have symptoms, especially when diabetes is diagnosed early. This is because the blood sugar level may rise so slowly that a person may not know that anything is wrong.
The most common symptoms of high blood sugar include:
You can get high blood sugar for many
reasons, including not taking your diabetes medicines, eating more than usual
(especially sweets), not exercising, or being sick or under a lot of stress.
If you're taking insulin or oral diabetes medicine, you can also have problems with low blood sugar. These symptoms include:
If your doctor thinks that you have type 2 diabetes, he or she will ask you questions about your medical history, do a physical exam, and order a blood test that measures the amount of sugar in your blood.
The key to treating type 2 diabetes is to keep blood sugar levels controlled and in your target range.
All of the following help to lower blood sugar:
It's also important to:
It seems like a lot to do—especially at first. You might start with one or two changes. Focus on checking your blood sugar regularly and being active more often. Work on other tasks as you can.
It can be hard to accept that you have diabetes. It's normal to feel sad or angry. You may even feel grief. Talking about your feelings can help. Your doctor or other health professionals can help you cope.
Health Tools help you make wise health decisions or take action to improve your health.
Learning about type 2 diabetes:
Living with type 2 diabetes:
Type 2 diabetes occurs when
your blood sugar (glucose) levels get too high because:
Your weight, how much physical activity you get, and your
family history may affect the way your body responds
High blood sugar can
happen if you:
Being pregnant can also make your blood sugar levels go up.
If you take insulin, you may have some mornings when your
blood sugar level is very high, even if it was low when you went to bed. This could be caused by
the dawn phenomenon or the Somogyi effect. Talk with
your doctor if this happens. You may need to check your blood sugar during the night to find out why your levels are high in the morning.
aren't likely to get low blood sugar unless
you take insulin or some kinds of
oral medicines that can cause low blood sugar. You may
get low blood sugar if you:
Some people who have type 2 diabetes may not have any symptoms early on. Many people with the disease don't even know they have it at first. But with time, diabetes starts to cause symptoms.
Common symptoms of high blood sugar
See more about symptoms of high blood sugar.
The higher your blood sugar rises, the more likely you are to have symptoms. If you have higher-than-normal blood sugar and don't drink enough liquids, you can get dehydrated. This can make you feel dizzy and weak, and it can lead to an emergency called a hyperosmolar state.
To learn what to do in an emergency, see When to Call a Doctor.
When your blood sugar is
too low, it can also cause problems. And it can happen suddenly. Quickly treating low
blood sugar can help you avoid passing out (losing consciousness). You
can pass out when your blood sugar gets very low.
Low blood sugar can also lead to a heart attack.
Common symptoms of low blood sugar include:
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. But you're not likely to get low blood sugar unless you take insulin or oral diabetes medicines.
Know what your results mean
Rhonda O'Brien, certified diabetes educator
As important as regular testing is, you also need to know what the
results mean and how to use them. "Look for patterns. If your blood sugar is
always high before lunch, take a look at what you had for breakfast. Maybe you
need to make some changes."—Rhonda
Learn blood sugar testing tips from Rhonda O'Brien.
When you have type 2 diabetes, your body still makes insulin. But as time goes on, your
pancreas may make less and less insulin, which will make it harder to keep your blood sugar in your target range. If your blood sugar gets too high and stays too high for too long, your risk for other health problems increases. Over time, high blood sugar can damage many parts of your body.
High blood sugar levels may cause temporary blurred vision. Blurry vision, floaters, or flashes of light may be a sign of
diabetic retinopathy, which can cause severe vision loss.
To learn more, see the topic Diabetic Retinopathy.
You may have less feeling in your feet, which means that you can injure your feet and not know it. Blisters, ingrown toenails, small cuts, or other problems that may seem minor can quickly become more serious.
If you develop serious infections or bone and joint deformities, you may need surgery (even amputation) to treat those problems. Common infections can quickly become more serious when you have diabetes.
High blood sugar damages the lining of blood vessels. This can lead to stroke, heart attack, or peripheral arterial disease. Erection problems can be an early warning sign of blood vessel disease and may mean a higher risk of heart 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.
Type 2 diabetes can raise your risk of depression. It may be caused by the stress of dealing with diabetes or by the effects that diabetes has on your body.
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 you can't change include:1
Risk factors you can change include:
Other health problems can put you at risk for type 2 diabetes. These are
also linked to
obesity and a lack of physical activity:
To see whether you are at risk for type 2 diabetes, see the website www.diabetes.org/diabetes-basics/prevention/diabetes-risk-test. If you are at risk, you can
discuss with your doctor how to make healthy changes in your life.
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.
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 blood glucose tests and hemoglobin A1c.
To make a diagnosis of type 2 diabetes, your doctor will use your blood test results and the American Diabetes Association (ADA) criteria. He or she will also ask you questions about your medical history and do a physical exam for type 2 diabetes.
You'll need to see your doctor every 3 to 6 months. At each visit you'll:
See a list of
tests to monitor type 2 diabetes to help you remember what to do and when.
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.
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 increases your risk for diabetic retinopathy.1 If you already have eye disease and
get pregnant, the disease can quickly get
Your treatment for
type 2 diabetes will change over time to meet
your needs. But the focus of your treatment will always be
to keep your blood sugar levels within your target range. That will help prevent complications from type 2 diabetes,
such as eye, kidney, heart, blood vessel, and nerve disease.
The keys to managing your type 2 diabetes are
Making big changes like quitting smoking or changing the way you eat is hard. But you can do it if you set small goals and celebrate your successes. For help, see the topic Change a Habit by Setting Goals.
Your treatment may change if you get pregnant. For example, some medicines could harm your baby. If your blood sugar gets too high while you're pregnant, your baby might have problems at birth. Talk with your doctor.
And you can successfully breast-feed your baby when you have type 2 diabetes.
One Woman's Story:
changed everything for me. The way I feel, my blood sugar, everything. It
really works. I never felt better, stronger, healthier, or happier in my
Read more about Gloria and how she manages her diabetes.
Many people have prediabetes before they have type 2 diabetes. If you're concerned about your risk, talk with your doctor. He or she will order tests to check your blood sugar levels. If you have prediabetes, you should be tested for type 2 diabetes every year. To learn more, see the topic Prediabetes.
You can take steps to prevent type 2 diabetes. Even small changes can make a difference, and it is never too late to start making healthier choices.
A healthy weight is one that is right for your body type and height
and is based on your
body mass index (BMI) and the size of your waist (waist circumference). Losing just 7% of your body weight can help reduce
your risk for type 2 diabetes.1 If you
are age 20 or older, use the
Interactive Tool: Is Your BMI Increasing Your Health Risks? to check
your BMI. To use the tool, you'll need to know your height, weight, and waist circumference.
Do activities that raise your
heart rate. Try to do
moderate activity at least 2½ hours a week. Or try to
vigorous activity at least 1¼ hours a week. It's fine
to be active in blocks of 10 minutes or more throughout your day and week.
include resistance exercises in your exercise program.2 Resistance exercises can include
activities like weight lifting or even yard work.
Walking groups or programs where you use a
pedometer to count the number of steps you take in a day are great ways to
start exercising and to stay motivated.
exercise planning form(What is a PDF document?) may help you and your doctor create a personalized exercise
Review the dietary guidelines for good health, which are good for everyone, including people who have prediabetes or type 2 diabetes.
If exercise, eating healthy foods, and being at a healthy weight don't help lower your blood sugar, you may need to take medicine. For people who have prediabetes, the medicine metformin can help prevent type 2 diabetes.
Making healthy choices is a big part of managing type 2 diabetes. The more you learn about the disease, the more motivated you may be to make good choices and follow your treatment plan.
Eat a balanced diet, and try to manage the amount of
carbohydrate you eat by spreading it out over the day.
The dietary guidelines for good health can help everyone form healthy eating habits, including people who have type 2 diabetes. It is especially important for people with type 2 diabetes to:
You don't have to join a gym to get fit or be active. There are many things you can do, such as walking or even vacuuming.
The American Diabetes
Association (ADA) recommends that you keep your blood sugar levels at:1
A continuous glucose monitor, or CGM, reports on your blood sugar at least every 5 minutes, day and night. And it sounds an alarm if it sees that your levels are headed out of range.
Having a record of your blood sugar over time can
help you and your doctor know how well your treatment is working and whether
you need to make any changes.
taking type 2 diabetes medicine or insulin, you will need to know
how to deal with low blood sugar and how to give yourself an insulin shot.
Check your feet and skin every day for
signs of problems. Nerve damage makes it hard to feel an injury or infection.
Trying to manage your type 2 diabetes isn't easy.
Some days you may feel like it's just too much work to do everything you need
to do. There will be times when you just don't feel like testing and tracking
your blood sugar.
It's normal to feel sad
or even angry sometimes when you have a health problem. Even though you've had a while to get
used to the idea of having type 2 diabetes, you may still have trouble adjusting. You
may find it hard to
When you feel sad, give yourself time to
grieve your losses. If you feel overwhelmed,
just try to focus on one day at a time. Do the best you can. You don't have to
If you're having trouble coping with your feelings,
try talking with a
counselor. A professional may make it easier to say
things you wouldn't talk about with friends or family.
If you have
symptoms of depression, such as a lack of interest in things you used to enjoy,
a lack of energy, or trouble sleeping, talk with your doctor. For more help,
see the topic
You might also want to:
One Man's Story:
As a grocery manager, Andy
is on his feet all day. He also likes to bowl and play basketball with his
buddies. He started thinking about what he would do if he couldn't walk, work,
or play. "It finally just hit me how serious this disease is. I couldn't keep
Read more about Andy and his diabetes routine.
Be aware of other things you can do to help yourself
Some people with
type 2 diabetes need pills (oral medicines)
to help their bodies make insulin, decrease
insulin resistance, or slow down how quickly
their bodies absorb carbohydrate.
You may take no
medicine, one medicine, or a few medicines. Some people need to take medicine
for a short time, while others always need to take medicine. How much medicine
you need depends on how well you can keep your blood sugar within
your target range. You may need more medicine over time, even if you have good control of your blood sugar.
Medicines can help you manage your
type 2 diabetes and other health problems, but only if you
take them correctly. It can be hard to keep track of
when and how to take your medicine, especially if you are taking more than one.
Maybe you aren't sure why you are taking a medicine or if it is working. Or you
might have trouble paying for your medicine. For help, see the topic Quick Tips: Taking Medicines Wisely.
have type 2 diabetes and a body mass index (BMI) greater than 35,
weight loss surgery may help you lose weight and
improve your type 2 diabetes control.1
Studies show that the large weight
loss provided by stomach surgery
(bariatric surgery) improves blood sugar control in
people who are very overweight.1
Some complications from type 2 diabetes may need surgical treatment. For example:
Avoid products that promise a "cure"
type 2 diabetes. For example, antioxidant supplements (vitamins E, C, and carotene) don't cure type 2 diabetes. The American Diabetes Association does not recommend taking them.1
If you hear about something new to help type 2 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.
These sources present information that is based on the analysis of a large body of medical evidence:
therapies may help relieve stress and muscle tension. They might help you feel better in general. But
they shouldn't be used as your only treatment for type 2 diabetes.
Talk with your doctor if you are using any of these
The Academy of Nutrition and Dietetics sets standards for all types of prescribed diets. The
organization produces a variety of consumer information, including videos. This group will help you find a registered dietitian in your area who
provides nutrition counseling.
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 Centers for Disease Control and Prevention (CDC) is
an agency of the U.S. Department of Health and Human Services. The CDC works
with state and local health officials and the public to achieve better health
for all people. The CDC creates the expertise, information, and tools that
people and communities need to protect their health—by promoting health,
preventing disease, injury, and disability, and being prepared for new health
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).
The National Library Service has established a national
network of cooperating libraries to provide a free library program of braille
and audio materials. Materials, including some magazines, in braille, large
print, or cassette can be borrowed postage-free by people who are eligible for
Prevent Blindness America assists the visually impaired
and provides consumer information on vision problems and vision aids.
Its website has information about eye health and safety for children
and adults. Many states have local affiliates.
CitationsAmerican Diabetes Association (2013). Standards of medical care in diabetes—2013. Diabetes Care, 36(Suppl 1): S11–S66.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.Other Works ConsultedAmerican Diabetes Association (2008). Nutrition recommendations and interventions for diabetes. Diabetes Care, 31(Suppl 1): S61–S78.American Diabetes Association (2013). Standards of medical care in diabetes—2013. Diabetes Care, 36(Suppl 1): S11–S66.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.Dixon JB, et al. (2008). Adjustable gastric banding and conventional therapy for type 2 diabetes. JAMA, 299(3): 316–323.Handelsman Y, et al. (2011). American Association of Clinical Endocrinologists medical guidelines for clinical practice for developing a diabetes mellitus comprehensive care plan. Endocrine Practice, 17(Suppl 2): 1–53. Available online: https://www.aace.com/publications/guidelines.Inzucchi SE, et al. (2012). Management of hyperglycemia in type 2 diabetes: A patient-centered approach. Diabetes Care, 35(6): 1364–1379.Kaul S, et al. (2010). Thiazolidinedione drugs and cardiovascular risks: A science advisory from the American Heart Association and American College of Cardiology Foundation. Circulation, 121(16): 1868–1877.Pignone M, et al. (2010). Aspirin for primary prevention of cardiovascular events in people with diabetes: A position statement of the American Diabetes Association, a scientific statement of the American Heart Association, and an expert consensus document of the American College of Cardiology Foundation. Circulation, 121(24): 2694–2701.Purnell JQ (2008). Obesity. In DC Dale, DD Federman, eds., ACP Medicine, section 3, chap. 10. Hamilton, ON: BC Decker.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.U.S. Preventive Services Task Force (2008). Screening for type 2 diabetes mellitus in adults: U.S. Preventive Services Task Force recommendation statement. Annals of Internal Medicine, 148(11): 846–854.
July 11, 2011
E. Gregory Thompson, MD - Internal Medicine & Jennifer Hone, MD - Endocrinology, Diabetes and Metabolism
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