HbA1c or glycated haemoglobin is the test used to monitor your blood glucose levels over the previous 2 – 3 months.
This is a different test to the blood glucose test that people with diabetes do frequently (often several times a day), usually with a finger prick and small device called a ‘glucometer’.
To use a cricketing analogy, we look at a cricketer’s batting average over the summer to see how they perform overall since looking at the number of runs in a single day does not give you a good indication of that athlete’s overall skill and performance. In the same way, a blood glucose test gives a snapshot of a level at a particular time, and the HbA1c test gives an indication of what has been happening over a longer period.
Some of the glucose in the blood binds to the haemoglobin inside your red blood cells. Therefore, conditions that affect your red blood cells or haemoglobin can affect your HbA1c results. Such conditions include for example anaemia, iron deficiency, vitamin deficiencies or kidney disease (amongst others).
If there is any possibility that you may have a condition affecting your red blood cells or haemoglobin you should consult with your doctor before taking an HbA1c test.
HbA1c tests should not be used for diagnosis of diabetes in the following cases: