Posted October 1, 2022 by Anusha ‐ 3 min read
The hemoglobin A1c test tells you your average level of blood sugar over the past 2 to 3 months. It's also called HbA1c, glycated hemoglobin test, and glycohemoglobin.
Other names of Hemoglobin A1C test
What is a Hemoglobin A1C (HbA1C) test?
A hemoglobin A1C (HbA1C) test is a blood test that shows what your average blood sugar (glucose) level was over the past two to three months.
Glucose is a type of sugar in your blood that comes from the foods you eat.
Your cells use glucose for energy. A hormone called insulin helps glucose get into your cells.
If you have diabetes your body doesn’t make enough insulin, or your cells don’t use it well.
As a result, glucose can’t get into your cells, so your blood sugar levels increase.
Glucose in your blood sticks to hemoglobin, a protein in your red blood cells.
As your blood glucose levels increase, more of your hemoglobin will be coated with glucose.
An A1C test measures the percentage of your red blood cells that have glucose-coated hemoglobin.
An A1C test can show your average glucose level for the past three months because:
Glucose sticks to hemoglobin for as long as the red blood cells are alive.
Red blood cells live about three months.
What is it used for?
An A1C test may be used to screen for or diagnose:
Type 2 diabetes
With type 2 diabetes your blood glucose gets too high because your body doesn’t make enough insulin to move blood sugar from your bloodstream into your cells, or because your cells stop responding to insulin.
Prediabetes means that your blood glucose levels are higher than normal, but not high enough to diagnosed as diabetes. Lifestyle changes, such as healthy eating and exercise, may help delay or prevent prediabetes from becoming type 2 diabetes.
Normal Hemoglobin A1c test values
For people without diabetes, the normal range for the hemoglobin A1c level is between 4% and 5.6%.
Hemoglobin A1c levels between 5.7% and 6.4% mean you have prediabetes and a higher chance of getting diabetes.
Levels of 6.5% or higher mean you have diabetes.
Procedure of Hemoglobin A1c test
A health care professional will take a blood sample from a vein in your arm, using a small needle.
After the needle is inserted, a small amount of blood will be collected into a test tube or vial.
You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
What do the results mean?
A1C results tell you what percentage of your hemoglobin is coated with glucose.
The percent ranges are just a guide to what is normal.
What’s normal for you depends on your health, age, and other factors.
Ask your provider what A1C percentage is healthy for you.
To diagnose diabetes or prediabetes, the percentages commonly used are:
Normal: A1C below 5.7%
Prediabetes: A1C between 5.7% and 6.4%
Diabetes: A1C of 6.5% or higher
Risk of Hemoglobin A1c test
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.