Hi Broads, hope this helps
The HbA1c test (hemoglobin A1c test, glycosylated hemoglobin A1c test, glycohemoglobin A1c test, or A1c test) is a lab test which reveals average blood glucose over a period of two to three months. Specifically, it measures the number of glucose molecules attached to hemoglobin, a substance in red blood cells.
The test takes advantage of the lifecycle of red blood cells. Although constantly replaced, individual cells live for about four months. So by measuring attached glucose in a current blood sample, average blood sugar levels over the previous two to three months can be determined.
HbA1c test results are expressed as a percentage,