Some people with diabetes perform a blood glucose test daily or more frequently. The HbA1c test is different. Both tests are important when managing diabetes.
The daily check is a finger prick test using a small glucose meter. This gives a snapshot of your blood sugar level at the time that you take the finger prick. Blood sugar levels for everyone go up and down during the day and night: when you eat, exercise, get stressed or are unwell. The daily check indicates the blood glucose level at the time that you take the finger prick.
The quarterly check – HbA1c test – measures your average blood sugar over the previous 2-3 months.
The glucose (sugar) that you have in your blood can attach to red blood cells (haemoglobin). When this happens, the glucose remains with the red blood cell for the lifespan of the cell (about 3 months). This is glycated haemoglobin or HbA1c.
A high HbA1c level indicates that there is more glucose attached to the red blood cells. A low HbA1c level indicates that there was less glucose attached. The HbA1c indicates the average blood sugar level over the last 3 months or so.
For people with diabetes the HbA1c test is taken every 3 or 6 months to check that any medication or lifestyle changes have been effective.