Hemoglobin A1C

About the Test

The hemoglobin A1C (HbA1C) test is a blood test that shows what the average glucose level was over the past two to three months. Glucose is a type of sugar in the blood that comes from what we eat. Our cells use glucose for energy. A hormone called insulin helps glucose get into the cells. If a patient has diabetes, their body doesn’t produce enough insulin, or the cells don’t use it well. As a result, glucose blood’ levels increase due to not being pushed into the cells. Increased blood glucose levels stick to hemoglobin, a protein in the red blood cells. As the blood glucose levels increase, more hemoglobin will be coated with glucose. The test can show the average glucose level for the past three months because glucose sticks to hemoglobin for as long as the red blood cells are alive(approximately three months). This makes the hemoglobin A1C test an important indicator of long-term glycemic control.