Whilst this raised glucose level is not so high that you have type 2 diabetes, you are at increased risk of developing type 2 diabetes when you have pre-diabetes. If you have pre-diabetes impaired glucose tolerance , your blood sugar glucose is raised beyond the normal range but it is not so high that you have diabetes.

However, if you have pre-diabetes you are at risk of developing type 2 diabetes. However, the glucose tolerance test is rarely used now.

The most commonly used test to identify pre-diabetes is now the HbA1c blood test. If you have impaired fasting glycaemia, you are also thought to have an increased risk of developing diabetes. Your risk of developing cardiovascular disease is also increased but this seems to be lower than if you have pre-diabetes impaired glucose tolerance.

NICE states that someone with a fasting blood glucose of 5. Our quiz will help you discover whether you are exhibiting some of the symptoms and evaluate your risk.

You are often found to have pre-diabetes after blood tests taken for another reason show that you have a raised blood sugar glucose level. Sometimes, your doctor may suggest that a screening blood test should be taken to check your blood glucose because they are worried that you may have some risk factors for pre-diabetes or diabetes.

Many people have pre-diabetes impaired glucose tolerance and because there are no symptoms, they do not know that they have it. Diabetes UK estimates that around seven million people in the UK have pre-diabetes. Pre-diabetes impaired glucose tolerance develops for the same reasons as type 2 diabetes see above.

There are various things that can increase your risk of developing pre-diabetes. They are the same risk factors as those for type 2 diabetes. They include:. Pre-diabetes is now most often diagnosed using a blood test called HbA1c.

See the separate leaflet called Tests for Blood Sugar Glucose and HbA1c for more details. Another test to diagnose pre-diabetes is the glucose tolerance test but this is much less often used now.

Read more in the separate leaflet called Glucose Tolerance Test. There is increasing evidence that if pre-diabetes impaired glucose tolerance is treated, it becomes much easier to prevent or delay it progressing to type 2 diabetes.

Also, it may be possible to prevent cardiovascular disease from developing. It is also very important to have a regular blood test to recheck your blood sugar glucose level in case you develop diabetes.

The frequency of the blood test will vary but you should discuss this with your doctor. A blood glucose test at least once each year is usually recommended. The NHS in England has developed the NHS Diabetes Prevention Programme for people with pre-diabetes.

This provides personalised support from a group of healthcare professionals. If you are diagnosed with pre-diabetes and live in England, you should be offered referral to this service. It involves at least 13 sessions over about 9 months, each lasting hours. You will be supported to set and achieve goals and make positive changes to reduce your risk of developing type 2 diabetes.

Most of the sessions will be run as face-to-face groups with other people who also have pre-diabetes and led by one or more experts. Lifestyle changes have been found to be the most effective way to stop pre-diabetes from developing into diabetes. Losing weight if you are overweight, and increasing your levels of physical activity, can help to reduce insulin resistance and therefore make the insulin that is produced more effective at controlling your blood glucose levels.

Public Health England advises minutes of physical activity each week, in bouts of 10 minutes or more. This might feel like a tall order, but it can be done in a way that becomes an enjoyable part of your life. There are also other lifestyle changes that you can make to reduce your cardiovascular disease risk.

These include:. Make sure that your blood pressure stays within the normal range. Have your blood pressure checked regularly with your practice nurse. A number of medical trials have looked at the use of various treatments with medicines for people with pre-diabetes to see if they can help to prevent diabetes and cardiovascular disease.

Lifestyle changes as indicated above are the most important thing if you are found to have pre-diabetes. However, the National Institute for Health and Care Excellence NICE has recommended that metformin should be used if a lifestyle-change programme isn't successful or isn't possible because of a disability or medical reasons.

A medicine called orlistat may occasionally also be recommended to help lose weight and therefore reduce the risk of developing diabetes. You will usually need a blood test to check your fasting blood sugar glucose level at least once a year.

This is to make sure that you have not developed diabetes. Your doctor is also likely to keep a check on any other risk factors that you may have for cardiovascular disease. So, they may monitor your weight and your blood pressure and also suggest a blood test to check your cholesterol and triglyceride levels.

In the meantime, if you develop any symptoms of diabetes , you should visit your doctor sooner. See the separate leaflets called Cardiovascular Disease Atheroma and Cardiovascular Health Risk Assessment for more details. Diagnosis of type 2 diabetes is definitively made by blood tests. Diagnosis requires two abnormal test results from the same sample or from two different samples.

Repeat the test using one of the following methods. Health care professionals may wish to observe patients with prediabetes whose condition is likely to progress, recommend lifestyle modifications, and retest in 3 to 6 months.

View the content below as a table in the PDF version PDF, With a coefficient of variation of 5. The A1C test is sometimes called the hemoglobin A1C, HbA1c, glycated hemoglobin, or glycohemoglobin test.

In some people, a blood glucose test may indicate a diagnosis of diabetes even though an A1C test does not. The reverse can also occur—an A1C test may indicate a diagnosis of diabetes even though a blood glucose test does not. Because of these variations in test results, health care professionals should repeat tests before making a diagnosis.

People with differing test results may be in an early stage of the disease, where blood glucose levels have not risen high enough to show on every test. This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases NIDDK , part of the National Institutes of Health.

NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by NIDDK is carefully reviewed by NIDDK scientists and other experts.

The NIDDK would like to thank: Randie Little, Ph.

Ask your doctor what your test results mean. If your test results show you have prediabetes, ask your doctor or nurse if the lifestyle change program offered through the CDC-led National Diabetes Prevention Program is available in your community.

You can also search for an online or in-person program. If your test results show you have type 1, type 2, or gestational diabetes, talk with your doctor or nurse about a detailed treatment plan—including diabetes self-management education and support services —and specific steps you can take to be your healthiest.

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Download Image [PNG]. National Diabetes Prevention Program Diabetes Articles Infographics. The OGTT is a two-hour test that checks your blood glucose levels before and two hours after you drink a special sweet drink.

It tells the doctor how your body processes sugar. Before people develop type 2 diabetes, they almost always have prediabetes—blood glucose levels that are higher than normal but not yet high enough to be diagnosed as diabetes.

Doctors sometimes refer to prediabetes as impaired glucose tolerance IGT or impaired fasting glucose IFG , depending on what test was used when it was detected. This condition puts you at a higher risk for developing type 2 diabetes and cardiovascular disease.

Some people with prediabetes may have some of the symptoms of diabetes or even problems from diabetes already. You usually find out that you have prediabetes when being tested for diabetes.

Some supplements or alternative therapies might be harmful if combined with certain prescription medications. Your health care provider can help you weigh the pros and cons of specific alternative therapies.

You're likely to start by seeing your primary care provider. He or she may refer you to a specialist in diabetes treatment endocrinologist , a dietitian or a certified diabetes educator. Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission.

Check out these best-sellers and special offers on books and newsletters from Mayo Clinic Press. This content does not have an English version. This content does not have an Arabic version. Diagnosis The American Diabetes Association ADA recommends that diabetes screening for most adults begin at age More Information A1C test Glucose tolerance test.

Request an appointment. Thank you for subscribing! Sorry something went wrong with your subscription Please, try again in a couple of minutes Retry. By Mayo Clinic Staff. Show references American Diabetes Association. Standards of medical care in diabetes — Diabetes Care. Centers for Disease Control and Prevention.

Accessed Oct. The surprising truth about prediabetes. Diabetes: 12 warning signs that appear on your skin. American Academy of Dermatology Association. Insulin resistance and prediabetes. National Institute of Diabetes and Digestive and Kidney Diseases. Type 2 diabetes. Diabetes tests and diagnosis.

Rett K, et al. Understanding prediabetes: Definition, prevalence, burden and treatment options for an emerging disease. Current Medical Research and Opinion. Mahat RK, et al. Health risks and interventions in prediabetes: A review.

Wallace AS, et al. Screening and diagnosis of prediabetes and diabetes in US children and adolescents. Magge SN, et al. Evaluation and treatment of prediabetes in youth. Journal of Pediatrics. Physical activity guidelines for Americans. Department of Health and Human Services.

The Australian type 2 diabetes risk assessment tool AUSDRISK External Link helps both health professionals and individuals to assess the risk of a person developing type 2 diabetes over the next 5 years. Pre-diabetes is diagnosed by a pathology blood test , organised through your doctor, that checks your blood glucose level.

Any blood glucose test that shows higher than normal blood glucose levels needs to be checked further. An oral glucose tolerance test OGTT is the best way to diagnose pre-diabetes. The results of the OGTT will show whether your blood glucose levels are in the normal, pre-diabetes or diabetes range.

Pre-diabetes, type 2 diabetes and heart disease can be prevented by making lifestyle changes, including:. Once you are diagnosed with pre-diabetes, lifestyle changes are most important. Your doctor should organise a repeat oral glucose tolerance test in 12 months, unless you develop symptoms of diabetes earlier.

If you do have some of the symptoms of diabetes then it is important to speak to your doctor about this. This page has been produced in consultation with and approved by:. Hypertension, or high blood pressure, can increase your risk of heart attack, kidney failure and stroke.

Diabetes and the build-up of glucose sugar in the blood can cause serious complications if left untreated. Good foot care and regular check-ups can help people with diabetes avoid foot problems.

Gestational diabetes is diabetes that occurs during pregnancy and usually disappears when the pregnancy is over. Many parents worry when their child with diabetes starts or returns to school.

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The information and materials contained on this website are not intended to constitute a comprehensive guide concerning all aspects of the therapy, product or treatment described on the website.

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Skip to main content. Home Diabetes. Diabetes - pre-diabetes. Actions for this page Listen Print. This content does not have an Arabic version. Overview The glucose tolerance test, also known as the oral glucose tolerance test, measures your body's response to sugar glucose. More Information Diabetes Dumping syndrome Gestational diabetes Polycystic ovary syndrome PCOS Prediabetes Type 2 diabetes Type 2 diabetes in children Show more related information.

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Show references Glucose tests. Lab Tests Online. Accessed Jan. Gestational diabetes. Mayo Clinic. American Diabetes Association. Standards of medical care in diabetes — Diabetes Care.

Masharani U. Diabetes mellitus and hypoglycemia. In: Current Medical Diagnosis and Treatment New York, N. American College of Obstetricians and Gynecologists.

Practice Bulletin No. Related Diabetes Dumping syndrome Gestational diabetes Polycystic ovary syndrome PCOS Prediabetes Type 2 diabetes Type 2 diabetes in children Show more related content.

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You may be diagnosed with prediabetes if your blood sugar is above normal but not high enough to be diabetes. You have prediabetes if you meet one of the following criteria: footnote 1.

Ask your doctor how often you need to be tested. It may be hard to tell what type of diabetes you have. If so, your doctor may do a C-peptide test or test for autoantibodies to diagnose type 1 diabetes or a slowly developing form of type 1 diabetes called latent autoimmune diabetes in adults LADA.

Some rare forms of diabetes are caused by a genetic problem. You may need genetic testing to diagnose them. This includes maturity onset diabetes of the young MODY. There are many types of MODY, depending on the gene that is affected. Author: Healthwise Staff Medical Review: E.

Gregory Thompson MD - Internal Medicine Kathleen Romito MD - Family Medicine Adam Husney MD - Family Medicine Matthew I.

Kim MD - Endocrinology David C. Lau MD, PhD, FRCPC - Endocrinology. Author: Healthwise Staff. Medical Review: E. This information does not replace the advice of a doctor.

Healthwise, Incorporated, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content. To learn more about Healthwise, visit Healthwise. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.

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footnote 1. You will be diagnosed with diabetes if you meet one of the following criteria:. Two tests are used to confirm the diagnosis of diabetes. You may be diagnosed with prediabetes if your blood sugar is above normal but not high enough to be diabetes.

You have prediabetes if you meet one of the following criteria: footnote 1. Ask your doctor how often you need to be tested. It may be hard to tell what type of diabetes you have. If so, your doctor may do a C-peptide test or test for autoantibodies to diagnose type 1 diabetes or a slowly developing form of type 1 diabetes called latent autoimmune diabetes in adults LADA.

Some rare forms of diabetes are caused by a genetic problem. You may need genetic testing to diagnose them. This includes maturity onset diabetes of the young MODY. There are many types of MODY, depending on the gene that is affected. Author: Healthwise Staff Medical Review: E.

Gregory Thompson MD - Internal Medicine Kathleen Romito MD - Family Medicine Adam Husney MD - Family Medicine Matthew I. Kim MD - Endocrinology David C. Lau MD, PhD, FRCPC - Endocrinology. Author: Healthwise Staff. Medical Review: E. This information does not replace the advice of a doctor. Healthwise, Incorporated, disclaims any warranty or liability for your use of this information.

Your use of this information means that you agree to the Terms of Use. Learn how we develop our content. To learn more about Healthwise, visit Healthwise. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated. ca Network. It looks like your browser does not have JavaScript enabled.

Please turn on JavaScript and try again. Main Content Related to Conditions Diabetes. Important Phone Numbers. Topic Contents Overview Related Information References Credits. Top of the page. Overview Doctors use blood tests and follow guidelines from experts to diagnose diabetes.

footnote 1 Criteria for diabetes You will be diagnosed with diabetes if you meet one of the following criteria: You have symptoms of diabetes and a blood sugar level equal to or greater than The reverse can also occur—an A1C test may indicate a diagnosis of diabetes even though a blood glucose test does not.

Because of these variations in test results, health care professionals should repeat tests before making a diagnosis. People with differing test results may be in an early stage of the disease, where blood glucose levels have not risen high enough to show on every test.

This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases NIDDK , part of the National Institutes of Health. NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public.

Content produced by NIDDK is carefully reviewed by NIDDK scientists and other experts. The NIDDK would like to thank: Randie Little, Ph. Sacks, M. This content compares the following tests fasting plasma glucose FPG test oral glucose tolerance test OGTT A1C test random plasma glucose RPG test These tests may be used to screen for and diagnose diabetes and to detect individuals with prediabetes.

Repeat the test using one of the following methods Repeat the same test or run a different test. Diagnosis is made based on the confirmed test. Uses Screening and diagnosis of prediabetes 1 5. Food and Drug Administration for diagnosis; however, they should only be considered in laboratories that are certified to perform moderate-to-high complexity tests to ensure testing proficiency.

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