How Does an A1C Blood Test Work?

A normal blood glucose level during the day is in the low to mid 100s, according to Virginia Mason Medical Center. While these readings help you know how much insulin to use or what choices to make at mealtime, they do not provide an overall picture of how well your diabetes is being controlled the way an A1c blood test can.

Function

• The A1c blood test provides you and your doctor with a sense of how well your blood sugars were controlled for the three months that precede the test.

Background

• Hemoglobin is a substance that carries oxygen in your red blood cells. When hemoglobin comes into contact with blood sugar, it forms a reaction with the glucose.

Identification

• Hemoglobin is considered to be glycated once it reacts with blood glucose. The term for glycated hemoglobin is A1c.

Effects

• When your blood sugar levels are high, more A1c is produced because there is more glucose available for hemoglobin to react with.

A1c Test

• The A1c blood test measures how much A1c is present in your body for the three-month period before the test. By comparing the results of this test each time you receive it, you are able to monitor how your control over your blood sugar improves or declines over time.