What is HbA1c?
HbA1c (glycosylated haemoglobin) is a measure of the amount of glucose attached to the body's red blood cells; it is present in everyone. It gives an indication of your blood glucose control over the last 2-3 months. The level of HbA1c in your body rises and falls in line with your blood glucose - the higher your HbA1c, the more glucose is attached to your red blood cells. Your HbA1c does not change rapidly because the red blood cells in your circulation last for around 3-4 months. Any increases and decreases in your HbA1c will happen over a period of at least 6 weeks.
HbA1c is recorded as mmol/mol, and sometimes as a percentage, while blood glucose is recorded in mmol/L. You may be used to seeing your HbA1c reported as a percentage, however from 1 October 2011, HbA1c changed to be given in mmol/mol. An HbA1c test is not the same as a blood glucose test.