How accurate is A1C?

The A1C test is a reliable measure of average blood sugar levels over the past 2-3 months. However, its accuracy can be influenced by several factors:

• Normal Range: A1C results are generally accurate for most people, with a normal range of 4-6%.

• Factors Affecting Accuracy: Certain conditions or situations can lead to inaccurate results:

  • Anemia (especially severe anemia)
  • Kidney or liver disease
  • Blood disorders (e.g., sickle cell anemia, thalassemia)
  • Pregnancy (early or late stages)
  • Medications (e.g., opioids, HIV drugs)
  • Recent blood loss or transfusions

• Clinical Use: Despite these factors, the A1C test is widely used for diagnosing prediabetes (5.7-6.4%) and diabetes (6.5% or higher) and for monitoring long-term blood sugar control in people with diabetes.

If you have any of the above conditions, your healthcare provider may recommend alternative tests, such as fasting blood glucose or oral glucose tolerance tests, for a more accurate diagnosis.