Prediabetes is a condition characterized by high blood sugar levels. Some diet and lifestyle habits can help you manage your blood sugar levels and prevent the condition from progressing to type 2 diabetes.
If you’ve received a diagnosis of prediabetes, you may wonder what that means. Prediabetes is a condition in which your blood glucose levels are above a typical range but not high enough for a diabetes diagnosis.
This may be difficult to know how it’s different from type 2 diabetes (T2D), which is often tied to higher blood sugar levels. Prediabetes doesn’t guarantee that you will eventually develop T2D, though there is a higher risk.
Prediabetes can also increase the chances of eventually developing other complications, including heart disease.
Correct diagnosis for prediabetes is important and can help determine what lifestyle changes and management options could work best for you. The tests used to check for prediabetes or diabetes can help determine a diagnosis.
The A1C test is a blood test that measures the percentage of sugar attached to hemoglobin, a protein in red blood cells.
The higher your A1C, the higher your average blood sugar levels have been over the past
The A1C test is also known by these names:
- hemoglobin A1c test
- HbA1c test
- glycosylated hemoglobin test
A normal A1C level is below 5.7%, which corresponds to an estimated average blood sugar level lower than 117 milligrams per deciliter (mg/dL).
An A1C of 5.7% to 6.4% may suggest prediabetes, while an A1C of 6.5% or more indicates T2D if the result is confirmed.
According to the American Diabetes Association (ADA), up to 25% of people with an A1C of 5.5% to 6% will develop type 2 diabetes in 5 years, and up to 50% of those with an A1C of 6% to 6.4% will.
If your results are questionable, a doctor will recheck your A1C on another day to confirm the diagnosis.
| Result | A1C | Estimated average blood glucose level (mg/dL) |
|---|---|---|
| normal A1C level | below 5.7% | below 117 |
| prediabetes A1C level | 5.7%–6.4% | 117 to 137 |
| diabetes A1C level | above 6.4% | above 137 |
The FPG test is a blood test that healthcare professionals perform after you have fasted overnight. It measures the sugar in your blood.
A normal fasting glucose test result is lower than 100 mg/dL. A result of 100 to 125 mg/dL indicates prediabetes, and one that’s 126 mg/dL or above indicates diabetes.
If your result is 126 mg/dL or above, you’ll have the test again on a different day to confirm the diagnosis.
| Result | FPG level (mg/dL) |
|---|---|
| normal FPG level | below 100 |
| prediabetes FPG level | 100 to 125 |
| diabetes FPG level | above 125 |
An RPG test is a blood test that healthcare professionals may perform any time of day when you are not fasting. It measures the sugar level in your blood at that moment.
An RPG result of 200 mg/dL or higher indicates diabetes, especially if you’re experiencing symptoms of diabetes such as excessive thirst, hunger, or urination.
If your level is higher, a doctor will use one of the other tests listed to confirm the diagnosis.
The OGTT takes a little longer than the other two glucose tests for diabetes. In this test, a healthcare professional draws your blood once after an overnight fast and again 2 hours after you drink a sugary beverage.
It’s usual for your blood sugar to rise after you consume the drink. However, normal blood sugar falls to below 140 mg/dL within 2 hours.
If your blood sugar level is 140 to 199 mg/dL, a doctor will diagnose prediabetes. A level of 200 mg/dL or higher indicates T2D.
| Result | Blood glucose level (mg/dL) |
|---|---|
| normal OGTT level | below 140 |
| prediabetes OGTT level | 140 to 199 |
| diabetes OGTT level | above 199 |
Prediabetes may lead to type 2 diabetes.
While you might not notice any symptoms until after you’ve developed T2D, management is a big part of prediabetes and preventing diabetes.
Prediabetes does not always progress to T2D. Healthy lifestyle habits can help you get and keep your blood sugar levels within a target range.