Understanding A1c: What It Is and Why It Matters

HbA1c is also known as glycohemoglobin or A1c. Hemoglobin is the protein that carries oxygen in your red blood cells. When there is too much glucose in your blood, it can attach to the hemoglobin. This changes the structure of the hemoglobin and makes it less able to carry oxygen.

The A1c test measures how much hemoglobin has been changed by glucose. The higher your A1c, the more glucose has been in your blood over time.

A1c is called "A1c" because it is the first hemoglobin variant to be identified by electrophoresis. The "A" stands for "adult," and the "1c" stands for "first component."