Prediabetes: What It Is and How to Reverse Course

A health worker checking a woman's blood pressure during a screening visit — Photo: U.S. Air Force photo by Airman 1st Class Clara Karwacinski via Wikimedia Commons (Public domain). Image credits

Last reviewed: October 9, 2026 · Sources: CDC, NIH/NIDDK, American Diabetes Association

Prediabetes is a common and often overlooked condition. It means your blood sugar is higher than normal but not yet high enough to be diagnosed as type 2 diabetes. The encouraging part is that prediabetes is often reversible, and the steps that help are practical and well studied. This guide explains what prediabetes is, how it is diagnosed, who is at risk, and what you can do about it.

What is prediabetes?

The CDC defines prediabetes as blood sugar levels that are higher than normal but not high enough for a type 2 diabetes diagnosis. It is a serious health condition because it raises the risk of type 2 diabetes, heart disease, and stroke.

The CDC reports that more than 2 in 5 American adults have prediabetes, and about 8 in 10 people with prediabetes do not know they have it.

What causes prediabetes?

Prediabetes is closely linked to insulin resistance. Insulin is the hormone that helps glucose move from the blood into your cells. With insulin resistance, cells in your muscles, fat, and liver do not respond normally to insulin. The pancreas makes more insulin to compensate. Eventually, the CDC explains, the pancreas cannot keep up, and blood sugar rises, setting the stage for prediabetes and later type 2 diabetes.

NIDDK's page on insulin resistance and prediabetes notes that excess weight, especially around the abdomen, and physical inactivity are major contributors, and that genetics, certain medicines, and some health conditions also play a role.

Symptoms

Most people with prediabetes have no clear symptoms. Some may have darkened skin in body folds such as the neck or armpits, a sign associated with insulin resistance. Because symptoms are rare, prediabetes often goes undetected until type 2 diabetes or another problem appears. Testing is the only reliable way to know.

Who is at risk?

The CDC lists these risk factors:

Having overweight
Being 45 years or older
Having a parent, brother, or sister with type 2 diabetes
Being physically active less than 3 times a week
Ever having gestational diabetes or giving birth to a baby who weighed more than 9 pounds
Having polycystic ovary syndrome

African American, Hispanic/Latino American, American Indian, Alaska Native, Pacific Islander, and some Asian American people are at higher risk. Other factors health professionals consider include high blood pressure, abnormal cholesterol levels, and a history of heart disease.

The CDC and ADA offer a short online risk test that you can take in about a minute. It is not a diagnosis, but it can tell you whether testing is a good idea.

How prediabetes is diagnosed

Prediabetes is diagnosed with the same blood tests used for diabetes. The thresholds below are those used by the American Diabetes Association and NIDDK for adults (non-pregnant):

Test	Normal	Prediabetes	Diabetes
A1C	Below 5.7%	5.7% to 6.4%	6.5% or higher
Fasting plasma glucose	99 mg/dL or below	100 to 125 mg/dL	126 mg/dL or higher
Oral glucose tolerance test (2-hour)	139 mg/dL or below	140 to 199 mg/dL	200 mg/dL or higher

A diagnosis is usually confirmed with a repeat test. Your health care provider will interpret results in the context of your overall health. Learn more about the A1C test from NIDDK.

Why prediabetes matters

Prediabetes does not always lead to type 2 diabetes, but without changes many people do progress. Even before diabetes develops, elevated blood glucose and the insulin resistance behind it are associated with higher risk of heart disease and stroke. Finding prediabetes gives you a chance to act early.

You can lower your risk

The most important message about prediabetes is that action works. The CDC says that if you have prediabetes, you can lower your risk of developing type 2 diabetes by:

Losing a small amount of weight if you have overweight. The CDC describes this as around 5% to 7% of body weight, about 10 to 14 pounds for a 200-pound person.
Getting regular physical activity. The CDC describes this as at least 150 minutes a week of brisk walking or a similar activity, such as 30 minutes a day, 5 days a week.

The National Diabetes Prevention Program

The CDC-led National Diabetes Prevention Program (National DPP) offers a structured lifestyle change program. Participants work with a trained coach and a group over about a year to learn healthier eating, increase activity, manage stress, and stay motivated. According to the CDC, the program can lower your risk of type 2 diabetes by 58%, or by 71% if you are over age 60. Programs are offered in person and online; ask your doctor or search for a CDC-recognized program near you.

Practical steps to start today

Move more

Activity helps muscles use glucose and improves insulin sensitivity. Brisk walking is one of the easiest ways to start. If 30 minutes at once feels like too much, break it into 10-minute walks after meals. Adding muscle-strengthening activities at least two days a week, as recommended in federal physical activity guidelines, also helps. See our exercise and diabetes guide.

Rethink your plate

There is no single "prediabetes diet," but helpful patterns include filling half your plate with nonstarchy vegetables, choosing whole grains over refined grains, including lean proteins and healthy fats, and limiting sugary drinks and highly processed foods. Our diabetes-friendly eating basics article explains the plate method.

Aim for modest, steady weight loss

You do not need to reach an "ideal" weight to benefit. Losing a modest percentage of body weight, as the CDC describes, can make a meaningful difference. Slow, steady changes you can keep are more effective than crash diets.

Sleep, stress, and smoking

Poor sleep and chronic stress can affect blood sugar and eating habits. Smoking increases the risk of type 2 diabetes and its complications. Addressing these areas supports your overall progress.

Get follow-up testing

Ask your provider how often you should be retested. Many people with prediabetes are advised to have their blood sugar checked at least yearly.

Can medicine help?

For some people at high risk, a health care provider may discuss medication in addition to lifestyle changes. This is an individual decision to make with your provider.

Key takeaways

Prediabetes means blood sugar is above normal but below the diabetes range, commonly an A1C of 5.7% to 6.4%.
It is very common and usually has no symptoms, so testing is important if you have risk factors.
Modest weight loss and regular activity can substantially lower the risk of type 2 diabetes.
Structured programs like the National DPP have strong evidence behind them.

Sources

Links to the sources cited above appear in the text. We rely on the Centers for Disease Control and Prevention (CDC), the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), and the American Diabetes Association (ADA).

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