What is prediabetes?

Prediabetes is the state that occurs when a person's blood glucose levels are higher than normal but not high enough for a diagnosis of diabetes. About 11 percent of people with prediabetes in the Diabetes Prevention Program standard or control group developed type 2 diabetes each year during the average 3 years of follow-up. Other studies show that many people with prediabetes develop type 2 diabetes in 10 years.

Prediabetes is a condition that causes higher blood glucose levels than normal. It’s estimated that 59.7 million Americans over age 20 suffer with prediabetes and most do not know they are at risk for diabetes. That’s because usually prediabetes has no signs or symptoms until damage is done to internal organs.

In diabetes, there is either too little insulin being produced (type 1 diabetes) or there is a resistance to the existing insulin levels in the blood (type 2 diabetes). Insulin is a hormone produced by the pancreas that facilitates the movement of sugar from the bloodstream into the cells of the body.

Prediabetes is a state where the blood glucose is higher than normal, however not high enough to be classified as diabetes. It can be diagnosed with basic blood work that is typically monitored by your primary care physician. What it demonstrates is an increased risk for the development of diabetes. Preventing the progression to diabetes is important and should be discussed with your healthcare provider. There are many simple lifestyle changes that can be made which have been demonstrated to prevent or slow down the progression and these should all be discussed with your healthcare provider.

William Lee Dubois

Technically, we define diabetes as a certain absolute blood sugar number.

One point over and you are a member of our club—we’ll mail you a T-shirt and a blood glucose monitor while supplies last. One point under and you aren’t diabetic.

But your blood sugar is way higher than a “normal” person’s yet not high enough to be diabetic; so what the Sam Hill do we do with you?

Most doctors will tell you that you have prediabetes, which sounds so harmless you probably won’t do diddly squat about it. There actually isn’t even a medical diagnosis, what we call an ICD-9 code, for prediabetes.

The closest I’ve been able to find is “abnormal blood glucose not otherwise classified.”

I don’t believe in prediabetes. If you fall into this range you are a T-2 diabetic that does not need medication yet; and it is better to accept that fact. So if your doctor told you that you had prediabetes, or borderline diabetes, I’m here to tell you that you can’t be a little bit pregnant.

Prediabetes is a condition in which blood glucose levels are higher than normal but not high enough for a diagnosis of diabetes. Prediabetes is also called impaired glucose tolerance (IGT) or impaired fasting glucose (IFG).

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If you have prediabetes, you have more sugar (glucose) in your blood than normal—but not so much that you can be diagnosed with diabetes. Glucose comes from the food you eat and is the body’s main source of fuel. Your high blood glucose is a sign that your body is having trouble getting energy from your food. Instead of moving easily into your cells, where it can be burned for energy, glucose is building up in your bloodstream.

Prediabetes is when the glucose (blood sugar) levels aren't quite high enough to be diagnosed as a diabetes, but they are still higher than normal. We do tests in our office called a glucose tolerance test where we give a patient a sugar load and monitor their levels over a two-hour period. If their sugars do elevate they are considered a prediabetic.

A prediabetic will become a diabetic if they don't change their lifestyle.

With prediabetes blood sugars are not normal, but they are not quite in the diabetes range. In this video, Steven Edelman, MD, director of Taking Control of Your Diabetes, explains why people should take a prediabetes diagnosis seriously.

Prediabetes refers to the syndrome of insulin resistance and elevated insulin levels that is usually associated with obesity and the accumulation of a certain kind of fat called abdominal, truncal or visceral fat. This is fat tissue that is deep in the abdominal cavity and is very different from subcutaneous fat, which is deposited under the skin.

Abdominal obesity and fat tissue produces certain hormones and other substances that together cause insulin resistance. This was a major surprise in medicine when it was discovered only 10 or 15 years ago. Prior to that, fat tissue was considered to be "metabolically inert", which means that it was just a storage tissue and didn't affect metabolism. This was very far from the truth, and visceral fat is now considered to be very active and complex metabolically. It produces a host of hormones (for example, leptin, ghrelin and adiponectin) and other factors (cytokines) that have major influences on metabolism.

The discovery that insulin resistance was the central "lesion" in type 2 diabetes led to a whole area of research that resulted in linking type 2 diabetes to high blood pressure, truncal or abdominal obesity, abnormal blood lipids (elevated triglycerides and low HDL cholesterol) and high waist to hip ratio (the "apple" body type). It was originally described by Gerald Reaven, MD, a professor of medicine at Stanford University, who named it Syndrome X to underscore how little understood it was and how it was more than just elevated blood sugars that caused disease. He wrote a book for the general public on this called Syndrome X, published by Simon and Shuster in 2000. Syndrome X is now also called metabolic syndrome and prediabetes, and the majority of people with type 2 diabetes have some or all of its features.

Dr. Jack Merendino, MD

The term prediabetes refers to someone who has abnormally high blood sugar, but not high enough to meet the diagnosis of diabetes. There are several criteria that apply. A fasting blood sugar (taken first thing in the morning when you have not eaten anything for about 8 to 10 hours) would normally be under 100. To meet the diagnosis of diabetes, you have to be higher than 126. A fasting blood sugar between 100 and 126 would qualify as prediabetes.

Since 2009, the hemoglobin A1c value, a blood test measuring average blood sugar levels and long used to monitor blood sugar control, has been used for the diagnosis of diabetes. A value of greater than 6.5 indicates diabetes, while normal is under about 6. Most people who eventually develop diabetes have blood sugars that rise gradually out of the normal range and into the prediabetes range first. An A1c value between 6 and 6.5 often means a person is making this transition, and most such people would be considered to have prediabetes.

Individuals who lose weight, exercise regularly and are careful about their diet can often prevent or slow the progression of prediabetes to diabetes.

Dr. Merle Myerson, MD
Cardiologist (Heart Specialist)

Cardiovascular specialist Dr. Merle Myerson explains the definition of prediabetes. Watch Dr. Myerson's video for important tips and information about heart health.


Dr. Reza Yavari, MD

Prediabetes is the early stage of diabetes where the pancreas is able to produce insulin, but it's not as effective in the body so blood sugars rise. Watch endocrinologist Reza Yavari, MD, discuss prediabetes and how doctors can test for it.


Prediabetes is a condition in which blood sugar levels are higher than normal, but not high enough to be classified as diabetes. Prediabetes may be related to too little insulin being produced or decreased response to insulin by the body. People diagnosed with prediabetes have a higher risk of developing diabetes in the future.

Prediabetes means that your blood glucose levels are higher than normal, but not high enough to be classified as type 2 diabetes. Not all individuals with prediabetes develop type 2 diabetes. Research has shown that losing weight and increasing physical activity can prevent or delay the onset of diabetes.

A person's blood sugar levels usually rise slowly and progressively over the years, reaching a range classified as prediabetes before they become high enough to signify diabetes. Prediabetes is diagnosed two ways: By elevated blood sugar levels in a person who has not eaten for at least eight hours (a condition called impaired fasting glucose) and by elevated blood sugar levels after an oral glucose tolerance test (a condition called impaired glucose tolerance). An estimated 57 million Americans have some form of prediabetes and, therefore, are much more prone to developing diabetes.

If you have prediabetes, your blood sugar (glucose) is higher than normal, but not high enough to be considered diabetes. Prediabetes is a wake-up call that type 2 diabetes could be in your future, but you can still prevent it. People with prediabetes also are at higher risk for heart disease, stroke and eye disease.

Stacy Wiegman, PharmD
Pharmacy Specialist
Prediabetes is a condition in which your blood sugar (glucose) levels are higher than normal, but not high enough to qualify as diabetes. It used to be called impaired glucose tolerance or impaired fasting glucose. The name was changed several years ago to emphasize the diabetes risk, because many people with prediabetes will develop diabetes. It's not inevitable, however. Studies show that people with prediabetes who lose excess weight, exercise regularly and eat a balanced diet are much less likely to develop diabetes. Normal fasting blood glucose is below 100 milligrams of glucose per deciliter of blood (mg/dL). Prediabetes is when that number rises to between 100 and 125, and diabetes is above 126.

This is a fasting blood sugar level between 101 and 126 and post-meal sugars more than 140 but less than 200. A combination of these means a diagnosis of prediabetes. If these criteria are met, a physician will advise a regimen of diet, exercise and weight loss to delay or prevent progression to diabetes.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.