The HbA1c test measures the average blood sugar level over the past 2-3 months by checking the percentage of haemoglobin coated with sugar (glycated haemoglobin). It is the gold standard for monitoring diabetes control.
Unlike fasting blood sugar which shows the current level, HbA1c provides a long-term picture of blood sugar management. It is used both for diagnosing diabetes and for monitoring how well diabetes is being controlled.