Ask the doctor: What's the difference between blood sugar and hemoglobin A1c?
Q. In your article on blood sugar control, you kept talking about hemoglobin A1c. I measure my blood sugar all the time, but my meter doesn't have a setting for a percentage reading. Is there a simple connection between blood sugar and hemoglobin A1c?
A. Blood sugar and hemoglobin A1c are connected, but they are different, too. Your blood sugar meter measures the concentration of glucose in the bloodstream at the instant you prick your finger. The reading is in milligrams of glucose per deciliter (a tenth of a liter) of blood, abbreviated as mg/dL. Blood sugar levels vary throughout the day. In people with diabetes, they can range from below 70 mg/dL to well above 200 mg/dL.
To continue reading this article, you must log in.
Subscribe to Harvard Health Online for immediate access to health news and information from Harvard Medical School.
- Research health conditions
- Check your symptoms
- Prepare for a doctor's visit or test
- Find the best treatments and procedures for you
- Explore options for better nutrition and exercise
I'd like to receive access to Harvard Health Online for only $4.99 a month.
Sign Me UpAlready a member? Login ».
Disclaimer:
As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles.
No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.