Whether or not you take insulin every day, it's important to check your progress and get the "big picture" of how well your diabetes is controlled. That's where knowing your A1C can help. The A1C test shows what your average blood glucose level has been over the past two to three months. It's a simple blood test that rounds out the daily ups and downs to show you and your doctor how well your diabetes treatment plan has been working.
What is hemoglobin A1C and why is it important to me?
Hemoglobin is a protein inside your red blood cells. It binds (or glycates) to sugars and carries oxygen from the lungs to the cells. When your blood sugar is high, more hemoglobin attaches to the sugars. This produces glycated hemoglobin, which is what the A1C test measures. Red blood cells stay in the bloodstream for about 120 days, or about four months. Measuring the glycated hemoglobin shows what's been happening over this time period. A higher A1C reading means your blood sugar levels have been high. A lower A1C reading indicates your blood sugar levels are likely under control.
What is a "good" A1C reading?
Hemoglobin A1C is measured in percentages. Your doctor may set a personalized goal for you depending on your age, risk of hypoglycemia and whether you have any complications. He or she may want your A1C levels in the 6 to 7 range if you are younger and healthier. Otherwise your doctor may want your levels between 7 and 8.
Although there are some over-the-counter A1C testing kits you can use, it's recommended that you have your doctor test your A1C. This way, your doctor can discuss the results with you and adjust your medication if necessary. The goal is to keep your A1C level as close to non-diabetic levels as possible without having episodes of low blood sugar or hypoglycemia. This will reduce your risk of diabetes-related complications, such as heart disease, kidney failure, nerve damage and eye disease.
Your doctor will go over your test results with you. If your results are high, your treatment plan may not be working. Review your diabetes care plan with your doctor. He or she may make adjustments to your plan to get your blood sugar levels in check.
How often do I need this test?
For people with diabetes that is well controlled, A1C should be tested at least twice a year (usually every 3 months for children and teenagers), or as often as your doctor advises. If your diabetes is not well controlled or your treatment plan has changed, your doctor may want to test your A1C levels up to four times or more a year. If you're taking insulin, the A1C test should be done in addition to regular blood glucose monitoring at home. Think about blood glucose testing like checking your watch and A1C like looking at your calendar.
Remember, checking your A1C is an important part of staying healthy with diabetes. Your results can tell you how well your treatment plan is working — and help your doctor decide whether a change is necessary. Talk with your doctor about how often you should have this test done.
Created on 08/01/2001
Updated on 02/14/2013
- American Diabetes Association. A1C.
- American Diabetes Association. Standards of medical care in diabetes — 2013. Diabetes Care. 2013;36:S11-S66.
- National Diabetes Education Program. Know your blood sugar numbers.
- Copeland, KC, et al. Clinical Practice Guideline Management of Newly Diagnosed Type 2 Diabetes Mellitus (T2DM) in Children and Adolescents. American Academy of Pediatrics. 2013;131;364-382.