The general director of Xin'an Clinic explains the glycated hemoglobin HbA1c: The red letter does not mean a mistake, it needs to be combined with historical reports and long-term management

2026/09/24 09:00

Yang Zongheng, the general director of Xin'an Clinic, said that when you see red letters next to "glycated hemoglobin HbA1c", don't blame yourself. Schematic diagram, the characters in the picture have nothing to do with the news. (Produced by Health Network; picture taken from freepik)

[Health Channel/Comprehensive Report] Yang Zongheng, the general director of Xin'an Clinic, said on the Facebook fan page "Dr. Yang Zongheng", "Doctor, I have been eating very light these days, why is my glycated hemoglobin still high?"

When you get the blood test report and see red letters next to "glycated hemoglobin HbA1c", don't blame yourself yet. This number reflects the average blood sugar in the past two to three months, and the impact in the last month is relatively large; just eating less a few days before the blood draw cannot represent the overall situation in the previous months.

Please read on...

What does glycosylated hemoglobin test for?

Glucose in the blood combines with heme in red blood cells. HbA1c measures the proportion of this type of hemoglobin, helping us understand blood sugar conditions over a period of time.

This single test usually does not require fasting; if other tests are scheduled at the same time, preparations must still be made according to the hospital's instructions.

What do you think of the numbers on the report?

For non-pregnant adults, the commonly used interpretation range is:

● Less than 5.7%: Prediabetes threshold not reached.

● 5.7% ~ 6.4%: belongs to the pre-diabetes range.

● Above 6.5%: reaching the threshold for diabetes diagnosis.

If there are no clear symptoms of hyperglycemia and the diagnostic threshold is reached on a single occasion, retesting or another test is usually required for confirmation.

People who have been diagnosed with diabetes must make judgments based on personal treatment goals. They cannot directly apply the above range and conclude that diabetes has disappeared.

The average value is ideal, but you still need to pay attention to blood sugar fluctuations

HbA1c does not give a complete picture of the highs and lows throughout the day. Some people have averages that are close to their target but may still experience hypoglycemia.

In addition, certain anemia, recent massive blood loss or transfusion, kidney failure, etc. may also affect accuracy. If the number is very different from the daily blood sugar measurement, please bring the relevant medical history and records back to the clinic for discussion.

Yang Zongheng reminded that when you see the red letter, you can do one thing first: find out the last report and take it with you for follow-up consultation.

We need to understand how the numbers are changing and identify tracking and treatment goals that are appropriate for you. Putting blood sugar care into your daily life will be more meaningful than a temporary rush a few days before blood draws.

Yang Zongheng explained that "glycated hemoglobin HbA1c" reflects the average blood sugar in the past two to three months. (Picture taken from shutterstock)