Archive · 20 Aug 2025
Understanding Confusing Blood Sugar Readings: Fasting vs. HbA1c
Sometimes blood sugar test results can be confusing.
Someone might have a slightly high fasting blood sugar but a high HbA1c, showing diabetes.
Fasting blood glucose shows a single point in time, while HbA1c reveals the average blood sugar over months.
High HbA1c means the person's blood sugar has been consistently high.
The doctor may suggest changes to eating, increasing exercise, and potentially medicines.
Early treatment can prevent heart issues, nerve damage, and other complications.
Fasting blood glucose of 107 mg/dL indicates prediabetes.
HbA1c above 7% signifies poorly controlled diabetes.
HbA1c reflects average blood sugar over two to three months.
Mismatched results may occur due to post-meal glucose spikes.
High HbA1c increases risks of serious health complications.
- Who
- Dr. Bhattacharya (senior consultant, endocrinology, Apollo Hospital, Delhi)
- What
- The interpretation of blood sugar tests, especially fasting glucose and HbA1c results.
- When
- The information is based on current medical knowledge.
- Where
- Delhi, India.
- Why
- To clarify how to interpret blood glucose and HbA1c test results and how to manage diabetes.
Importance of Testing
Importance of Monitoring
Fasting Glucose vs. HbA1c
Importance of Testing
Fasting glucose gives a single snapshot of the blood sugar levels.
Importance of Monitoring
HbA1c indicates the average levels over months; more reliable for the risk.
- Fasting blood glucose (normal)
- < 100 mg/dL
- Fasting blood glucose (reported)
- 107 mg/dL (prediabetes)
- HbA1c (normal)
- < 5.7%
- HbA1c (diabetes diagnosis)
- > 6.5%
- HbA1c (reported)
- > 7% (diabetes)
- Expert
- Dr. Bhattacharya
