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Home > Fitness & Health > Health Library > Type 2 Diabetes
Type 2 diabetes happens when your body can't use insulin the right way. Over time, 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 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.
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 to insulin.
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.
You 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 include:
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 other 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:
Risk factors you can change include:
Other health problems can put you at risk for type 2 diabetes:
To see whether you are at risk for type 2 diabetes, see the website www.diabetes.org/are-you-at-risk/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.
If it is hard to tell if you have type 2 or type 1 diabetes, your doctor may do a C-peptide test or test for autoantibodies. (Autoantibodies are produced when the body's immune system does not work right.) These tests can help diagnose type 1 diabetes.
There are several types of autoantibodies, and some people may have them even before they show symptoms of type 1 diabetes. For people with a parent or sibling with type 1 diabetes, testing for autoantibodies and a higher-than-normal blood sugar level may be done to screen for an early stage of type 1 diabetes.
Some rare forms of diabetes (not type 1 or type 2 diabetes) are caused by a genetic problem and may need genetic testing to diagnose them.
You'll need to see your doctor every 3 to 6 months. At each visit you'll:
Your doctor might suggest a cholesterol and triglyceride test based on your age or your risk for heart disease. Talk to your doctor about when a cholesterol test is right for you.
For more information, see When to Have a Cholesterol Test.
See a list of tests to monitor 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. And if your health is changing and you have complications from diabetes, work with your doctor to make the right medical decisions for you. With your health and quality of life in mind, problem-solve and plan with your doctor.
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. If you already have eye disease and get pregnant, the disease can quickly get worse.
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 to:
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 breastfeed your baby when you have type 2 diabetes.
One Woman's Story:
"Exercise really 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 life."— Gloria
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. 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 do 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.footnote 2
If your doctor says it's okay, then try to do muscle-strengthening exercises at least 2 times a week. These exercises include push-ups and weight training. You can also use rubber tubing or stretch bands. You stretch or pull the tubing or band to build muscle strength. Be sure to work the major muscle groups: legs, hips, back, abdomen, chest, shoulders, and arms.
Walking groups or programs are great ways to start exercising and to stay motivated.
Using an exercise planning form may help you and your doctor create a personalized exercise program.
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 healthy foods
Eat a balanced diet, and try to manage the amount of carbohydrates you eat by spreading them 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.
Test your blood sugar
Work with your doctor to set your own target blood sugar range.
A continuous glucose monitor, or CGM, checks and records blood sugar day and night. Most CGMs sound an alarm if blood sugar levels are moving out of target 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.
Take medicines, if you need them
Insulin and some diabetes medicines may cause low blood sugar.
Check your feet and skin daily
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 stay motivated.
When you feel sad, give yourself time to adjust to 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 be perfect.
Get the support you need
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 Depression.
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 ignoring it."— Andy
Read more about Andy and his diabetes routine.
Be aware of other things you can do to help yourself stay healthy.
Some people with type 2 diabetes need medicines to help their bodies make insulin, decrease insulin resistance, or slow down how quickly their bodies absorb carbohydrates.
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.
Experts recommend weight-loss surgery for people who have type 2 diabetes if their:footnote 3
If you are Asian, your doctor may recommend surgery with a lower BMI. Studies have shown that the risks from being overweight start at a lower BMI in people of Asian background.
Some complications from type 2 diabetes may need surgical treatment. For example:
Avoid products that promise a "cure" for 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.footnote 4
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:
Some complementary 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 treatments:
American Diabetes Association (2019). Standards of medical care in diabetes—2019. Diabetes Care, 42(Suppl 1): S1–S193. Accessed December 17, 2018.
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.
Rubino F, et al. (2016). Metabolic surgery in the treatment algorithm for type 2 diabetes: A joint statement by international diabetes organizations. Diabetes Care, 39(6): 861–877. DOI: 10.2337/dc16-0236. Accessed June 30, 2016.
American Diabetes Association (2019). Standards of medical care in diabetes—2019. Diabetes Care, 42(Suppl 1): S1–S193. Accessed December 17, 2018.
Current as of:
December 20, 2019
Author: Healthwise StaffMedical Review: E. Gregory Thompson MD - Internal MedicineKathleen Romito MD - Family MedicineMartin J. Gabica MD - Family MedicineAdam Husney MD - Family MedicineDavid C.W. Lau MD, PhD, FRCPC - Endocrinology
Current as of: December 20, 2019
Author: Healthwise Staff
Medical Review:E. Gregory Thompson MD - Internal Medicine & Kathleen Romito MD - Family Medicine & Martin J. Gabica MD - Family Medicine & Adam Husney MD - Family Medicine & David C.W. Lau MD, PhD, FRCPC - Endocrinology
To learn more about Healthwise, visit Healthwise.org.
© 1995-2020 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
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