The gap between the two is a number on a lab report, not a feeling — and the tests, the follow-up schedule and the treatment options differ at each stage.
Prediabetes means your blood glucose (sugar) is higher than normal but not high enough to be diagnosed as diabetes, according to the CDC. Diabetes is a chronic — long-lasting — condition that affects how your body turns food into energy, also per the CDC. The two are measured with the same blood tests; what separates them is where your result falls on the scale.
Below is a side-by-side look at what each term means, how each is identified, and what usually happens after each result. Your own numbers, risk factors and next steps are for your doctor to interpret with you.
Prediabetes vs. Diabetes
Question
Prediabetes
Diabetes
What it is
Blood glucose higher than normal but not high enough to be diagnosed as diabetes (CDC, undated); the NIDDK calls it an intermediate stage in the development of type 2 diabetes
A chronic health condition that affects how your body turns food into energy (CDC, undated); the CDC describes three main types — type 1, type 2, and gestational (diabetes during pregnancy)
What causes it
Often insulin resistance, meaning the body does not use insulin — the hormone that moves glucose out of the blood — as well as it should
In type 2, the body does not make enough insulin or does not use it well, so too much glucose stays in the blood (NIDDK, undated); MedlinePlus lists overweight or obesity, low physical activity, and genetics and family history among contributing factors. Type 2 accounts for about 90% to 95% of diagnosed cases and type 1 for about 5% to 10% (CDC, undated)
A1C result
5.7% to 6.4% (NIDDK, undated)
6.5% or above (NIDDK, undated)
Fasting plasma glucose (blood drawn after not eating overnight)
100 to 125 mg/dL (NIDDK, undated)
126 mg/dL or higher, repeated for confirmation (NIDDK, undated)
Oral glucose tolerance test (blood sugar two hours after a measured sugar drink)
140 to 199 mg/dL (NIDDK, undated)
A result above that range, with confirmation as your provider directs
Who tends to be tested
The NIDDK notes testing may be ordered if you are age 35 or older, or have overweight or obesity plus other risk factors
The same screening tests are used; the CDC has estimated 29.1 million people in the US with diagnosed diabetes, including 28.8 million adults 18 or older
What treatment can involve
The American Diabetes Association reports the National Diabetes Prevention Program lifestyle change program has been shown to reduce the risk of developing type 2 diabetes by 58% (71% in those 60 and older) in people with prediabetes
The ADA describes an eating plan, physical activity, and oral or injectable medications — including insulin — to help meet target blood glucose levels. Metformin (brand name Glucophage) is one commonly prescribed oral option; whether any medication fits you is your prescriber's decision
Follow-up
The NIDDK advises adults and children diagnosed with prediabetes be tested for type 2 diabetes every year
Ongoing monitoring of blood glucose and A1C on a schedule set by your care team
Reference ranges can vary somewhat by laboratory, by age, and in pregnancy, and the cutoffs above come from US guidance; other countries report A1C in mmol/mol and may use different thresholds. Guideline editions are also revised — the American Diabetes Association updates its Standards of Care yearly.
Get medical help the same day, or go to an emergency department, if you have vomiting you cannot keep fluids down, fast deep breathing, fruity-smelling breath, severe drowsiness or confusion. If you take insulin or another glucose-lowering medication, sweating, shaking and confusion can signal low blood sugar and also need prompt attention.
Why the Confusion Happens
The clearest reason is the word itself: "prediabetes" contains "diabetes," so it sounds like a milder version of the same diagnosis rather than a separate category. The NIDDK defines prediabetes as blood glucose levels higher than normal but not high enough to be diagnosed as type 2 diabetes — a range, not a weaker form.
The second reason is that both are found with the same tests, on the same continuous scale. One A1C blood draw can return either label depending on where it lands, and the NIDDK's boundary between the two is a single tenth of a percentage point — 6.4% versus 6.5%. The same is true for fasting plasma glucose: 125 mg/dL versus 126 mg/dL. Numbers that close make the two results feel like one thing.
Technical names add to it. The American Diabetes Association describes prediabetes using the terms impaired fasting glucose (IFG), defined as fasting levels of 100 to 125 mg/dL, and impaired glucose tolerance (IGT), 2-hour levels of 140 to 199 mg/dL during a 75-gram glucose tolerance test. Both contain "glucose," neither contains "prediabetes," and a report listing "IFG" is easy to read as a diabetes diagnosis.
Finally, neither term reliably announces itself with symptoms, and informal phrases like "borderline" or "a touch of sugar" get applied to both. If you are unsure which term your result falls under, ask your provider to show you the number, the unit, and the range that lab uses.
Frequently asked questions
Is prediabetes just mild diabetes?
This question is about prediabetes, which is its own category rather than a grade of diabetes. The CDC defines it as blood glucose higher than normal but not high enough to be diagnosed as diabetes, and the NIDDK describes it as an intermediate stage in the development of type 2 diabetes. What it means for you — including whether more testing is needed — is something your healthcare provider interprets alongside your other risk factors.
My A1C came back at 6.4%. Which one is that?
That result sits in the prediabetes band, not the diabetes band: the NIDDK lists 5.7% to 6.4% as prediabetes and 6.5% or above as diabetes. A1C assays can vary between laboratories, and a borderline value is often repeated or paired with a fasting glucose test before anything is concluded. Your doctor decides what confirmation, if any, your result needs.
If I have prediabetes, will I get diabetes?
This one is about what typically follows a prediabetes result, and it is not a fixed path. The NIDDK advises that adults and children with prediabetes be tested for type 2 diabetes every year, and the American Diabetes Association reports that the National Diabetes Prevention Program lifestyle change program has been shown to reduce the risk of developing type 2 diabetes by 58%, and by 71% in people 60 and older. Your provider can tell you what follow-up schedule applies in your case.
Desmond writes about sleep, stress, and the slow erosion of both in modern life. He's most interested in the gap between what people know they should do and what actually gets them to do it.
