A fasting blood glucose of 108 mg/dL falls in the prediabetes range. According to the American Diabetes Association, fasting glucose between 100 and 125 mg/dL indicates impaired fasting glucose — a form of prediabetes. Your blood sugar is higher than normal but has not yet reached the diabetes threshold of 126 mg/dL.
Where 108 mg/dL Falls on the Scale
| Fasting Glucose Level | Classification | What It Means |
|---|---|---|
| Below 100 mg/dL | Normal | Blood sugar regulation is working properly |
| 100-125 mg/dL | Prediabetes | Impaired fasting glucose — your 108 is here |
| 126 mg/dL or higher | Diabetes | Diabetes (confirmed with a repeat test) |
At 108 mg/dL, you are about midway through the prediabetes range. This is a meaningful signal from your body that insulin resistance is developing, but you have significant room to act before reaching the diabetes threshold.
What This Number Actually Means
A fasting glucose of 108 mg/dL means that after 8 or more hours without eating, your blood still has more glucose than it should. In a healthy metabolic system, your liver releases just enough glucose overnight to fuel your brain and organs, and insulin keeps levels below 100 mg/dL.
When this system starts to break down — usually because your cells have become less responsive to insulin (insulin resistance) — glucose builds up in the blood. Your pancreas compensates by producing more insulin, but it can’t quite keep up, resulting in that 108 reading.
Important context: a single fasting glucose measurement is a snapshot. Stress, poor sleep, illness, and the “dawn phenomenon” (a natural early-morning rise in blood sugar) can all influence a single test. This is why your doctor will likely want to confirm the result.
What to Do Next
Step 1: Get an A1C Test
While fasting glucose captures one moment, an A1C test measures your average blood sugar over the past 2-3 months. This gives a more complete picture. An A1C between 5.7% and 6.4% confirms prediabetes. Ask your doctor to add this test if it wasn’t already part of your blood work.
Step 2: Understand Your Risk Factors
Talk to your doctor about your overall diabetes risk profile. Key factors include:
- Family history of type 2 diabetes
- Being overweight, especially carrying weight around your midsection
- Physical inactivity
- Age over 45
- History of gestational diabetes
- Polycystic ovary syndrome (PCOS)
Step 3: Start Lifestyle Changes
The CDC’s Diabetes Prevention Program has shown that lifestyle changes can reduce diabetes risk by 58%. Here’s where to start:
- Reduce refined carbohydrates: Swap white bread, white rice, and sugary cereals for whole grain alternatives. Limit added sugars.
- Increase fiber intake: Aim for 25-30 grams daily from vegetables, legumes, and whole grains. Fiber slows glucose absorption.
- Move more: Start with 150 minutes per week of moderate activity like brisk walking. Even a 15-minute walk after meals can lower post-meal blood sugar.
- Lose a modest amount of weight: If overweight, losing just 5-7% of body weight (10-14 pounds for a 200-pound person) has a dramatic effect on blood sugar.
For a detailed eating plan, see our guide on diet and nutrition for prediabetes.
Can You Bring 108 Back to Normal?
Yes. Prediabetes is reversible, and a fasting glucose of 108 is early enough that meaningful improvement is very achievable. Many people bring their fasting glucose below 100 mg/dL within 3-6 months of consistent lifestyle changes.
The key is consistency rather than perfection. Small, sustained improvements in diet and activity level add up to significant metabolic changes over time.
When to Be Concerned
A fasting glucose of 108 mg/dL is a warning sign, not an emergency. However, you should seek prompt medical attention if you experience:
- Extreme thirst or frequent urination
- Unexplained weight loss
- Blurred vision
- Numbness or tingling in hands or feet
- Wounds that heal slowly
These symptoms could indicate that blood sugar has risen higher than your fasting glucose alone suggests. For more about glucose level ranges, see our guide on prediabetes glucose levels.
The Bottom Line
A fasting glucose of 108 mg/dL is in the prediabetes range — it’s a clear signal that your blood sugar management needs attention, but it’s far from a diabetes diagnosis. Your most important next step is confirming this result with your doctor and getting an A1C test for a broader view. From there, straightforward lifestyle changes — better food choices, regular physical activity, and modest weight loss if needed — can bring your numbers back to normal. At 108, you have caught this early enough to make a real difference.
