What are the normal, prediabetic, and diagnostic values for fasting and postprandial blood glucose?

Hello! Paying attention to your blood sugar is a great habit—it's one of the "barometers" of our health. Let me break down these values for you in simple terms.

The blood sugar levels we usually talk about focus on two key time points: fasting and post-meal.

Fasting Blood Glucose (FBG): This is measured in the morning after waking up, before eating or drinking anything (after fasting for at least 8-10 hours). It reflects your body's baseline blood sugar level in a "resting" state.
Postprandial Blood Glucose (PBG): This typically refers to the blood sugar level measured 2 hours after taking the first bite of a meal. It shows how well your body processes food (especially carbohydrates) and indicates how effectively your insulin is working.

The table below makes it clear at a glance. The unit is mmol/L (millimoles per liter), the most commonly used unit in hospitals in China.

Blood Sugar Level Reference Table

Status	Fasting Blood Glucose (mmol/L)	2-Hour Postprandial Blood Glucose (mmol/L)	Explanation
✅ Normal Range	< 6.1	< 7.8	Congratulations! Your blood sugar is well controlled. Keep up the healthy lifestyle.
⚠️ Prediabetes	6.1 ~ 6.9	7.8 ~ 11.0	This is a "critical juncture"! Your body is sounding the alarm, but it's not diabetes yet. This is the golden period for reversal and intervention!
❌ Diabetes Diagnosis	≥ 7.0	≥ 11.1	If readings consistently reach this level, see a doctor promptly. Diagnosis will be confirmed with other tests.

Important Reminders

Don't panic over a single reading: Don't stress if one reading is high. Factors like a big meal the night before, poor sleep, or illness can affect your fasting blood sugar the next day. Diagnosing diabetes requires multiple readings taken at different times and must be confirmed by a doctor.
"Prediabetes" is an opportunity, not a sentence: Many people panic at the word "prediabetes." Actually, it's good news—it's a warning that without lifestyle changes, you could develop full diabetes! At this stage, diet and exercise can often bring blood sugar back to normal and help you avoid medication.
Another key indicator: Besides the two above, doctors also look at Glycated Hemoglobin (HbA1c). Unlike blood sugar, it doesn't fluctuate easily and reflects your average blood sugar level over the past 2-3 months. It's the "gold standard" for assessing long-term blood sugar control.
- Normal: < 6.0%
- Prediabetes: 6.0% - 6.4%
- Diabetes: ≥ 6.5%
Hospital venous blood tests are definitive: Finger-prick tests using home glucose meters measure capillary blood and can have some error. Final diagnosis relies on venous blood test results from a hospital.

Hope this information helps! Stay aware and live healthily!