What is being tested?
As glucose circulates in your blood, some of it spontaneously binds to haemoglobin (the protein that carries oxygen in your red blood cells). This combination is called haemoglobin A1c (HbA1c). The amount of HbA1c formed is directly related to the amount of glucose in your blood. If your diabetes is not well controlled, your blood glucose levels are high, causing higher HbA1c levels. HbA1c levels do not change quickly since red blood cells live for 3-4 months. Because of this, the amount of HbA1c in your blood reflects the average amount of glucose in your blood during the last few months.

How is the sample collected for testing?
Your blood may be drawn from a vein in your arm or, in some cases, a drop of blood from a finger-prick may be used.