Prediabetes is a state in which blood glucose is higher than normal but not yet high enough to meet the criteria for type 2 diabetes. According to the American Diabetes Association, it can be identified by an A1c of 5.7 to 6.4 percent, a fasting plasma glucose of 100 to 125 mg/dL, or a 2-hour oral glucose tolerance test result of 140 to 199 mg/dL.

Does prediabetes always turn into diabetes?

No. Prediabetes raises the risk of developing type 2 diabetes, but it is often modifiable. Many people can lower their risk through changes in diet, physical activity, and other habits. A clinician can help interpret your results and advise on next steps.

Can you have prediabetes without symptoms?

Yes. Prediabetes is frequently silent, meaning many people have no noticeable symptoms. This is why screening with a blood test is the main way it is detected, especially for people with risk factors.

Prediabetes · basics

What Is Prediabetes?

6 min read · Updated July 2026

Prediabetes is a stage of glucose regulation that sits between normal and type 2 diabetes: blood sugar runs higher than it should, but not yet high enough to meet the diagnostic threshold for diabetes. It is common, frequently silent, and — importantly — often modifiable with the right support.

A simple definition

The word "prediabetes" describes a specific, measurable range. Your body still makes insulin and still moves glucose out of the bloodstream, but the process has become less efficient than it should be. Glucose lingers a little higher and a little longer than it does in someone with fully typical metabolism. It is not diabetes, and having it does not guarantee that diabetes will follow — but it is a recognised early signal that metabolic risk is rising.

For a fuller picture of how prediabetes fits alongside related terms, see the prediabetes guide, which acts as the hub for this topic, and our explainer on dysglycemia, the broader umbrella that prediabetes belongs to.

Higher than normal, below diabetes

The clearest way to understand prediabetes is as a band on a spectrum. On one side is normal glucose regulation. On the other is type 2 diabetes, defined by specific cutoffs. Prediabetes occupies the space in between — clearly elevated, but short of the diabetes line.

Prediabetes is a band, not a single number. It marks glucose that is elevated but has not yet reached the diabetes threshold.

The three ways prediabetes is defined

Prediabetes can be identified through any of three standard blood tests. The American Diabetes Association (ADA) publishes the widely used cutoffs:

A1c (HbA1c): 5.7–6.4% is the prediabetes range. Below 5.7% is considered normal, and 6.5% or higher is in the diabetes range. A1c reflects average glucose over roughly the previous two to three months. You can read more in our piece on the prediabetes A1c range.
Fasting plasma glucose (FPG): 100–125 mg/dL after an overnight fast is called impaired fasting glucose. At or above 126 mg/dL falls in the diabetes range. See impaired fasting glucose for detail.
Oral glucose tolerance test (OGTT): a 2-hour value of 140–199 mg/dL after a glucose drink is called impaired glucose tolerance. At or above 200 mg/dL falls in the diabetes range. See impaired glucose tolerance.

These three tests measure glucose in different ways, so it is possible to be flagged by one and not another. Our guide on how prediabetes is diagnosed explains why results can vary and how clinicians confirm them.

It's common — and often silent

Prediabetes is widespread. Public health bodies such as the U.S. Centers for Disease Control and Prevention (CDC) have reported that a large share of adults with prediabetes are unaware they have it, in part because it usually produces no clear symptoms. A person can spend years in the prediabetes range and feel entirely well.

That quiet quality is exactly why screening matters. Because there is often nothing to feel, a blood test is typically the only way to know. Our overview of prediabetes symptoms discusses the subtle signs that sometimes appear, and why their absence should not be reassuring on its own.

Why it's often modifiable

Perhaps the most encouraging feature of prediabetes is that the earlier end of the spectrum tends to respond to everyday changes. Structured lifestyle approaches — centred on eating patterns, physical activity, sleep, and weight — are commonly recommended, and research summarised by the CDC and ADA supports their role in reducing the risk of progression to type 2 diabetes. We cover practical ground in our articles on prediabetes diet and prediabetes exercise, and on the broader question of whether prediabetes can be reversed.

None of this is a promise. Individual results vary, and prediabetes is best managed in partnership with a qualified clinician who can interpret your specific numbers in the context of your history. Tools like continuous glucose monitoring are increasingly used, under professional guidance, to add day-to-day context to that conversation. Endobits is clinical decision-support software used under clinician oversight — it supports interpretation, it does not diagnose or treat.

Wondering where your numbers fall?

See how glucose data can be put in context against the standard ranges — a starting point for a conversation with your clinician.

Check your glucose

Sources

American Diabetes Association — Understanding Diagnosis (A1c, FPG, and OGTT criteria). Centers for Disease Control and Prevention — Prediabetes — Your Chance to Prevent Type 2 Diabetes. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) — Prediabetes & Insulin Resistance.

This article is educational and not medical advice. Diagnostic thresholds are attributed to the American Diabetes Association and may be updated over time. Talk to a qualified healthcare provider about your health. Endobits is clinical decision-support software used under clinician oversight, not a diagnostic device.