The HbA1C (Hemoglobin A1C) test, also known as the glycated hemoglobin or glycohemoglobin test, is a blood test that measures your average blood glucose level over the preceding two to three months.
Unlike the Fasting Glucose or Postprandial tests, which provide a snapshot of your sugar level at a single point in time, the HbA1C gives a long-term assessment of how well your blood sugar has been controlled.
When glucose enters the bloodstream, it attaches to the hemoglobin protein inside your red blood cells. Since red blood cells live for about 120 days, the HbA1c test measures the percentage of hemoglobin that has glucose attached ("glycated"), reflecting the average glucose concentration over that time period.
