Checking your blood glucose at home with a meter tells you what your blood sugar level is at any one time. But, the A1C test gives you a picture of what your average blood glucose control was for the past 2 to 3 months if you are diabetic. The results give you a good idea of how well your diabetes treatment plan is working. If you are not diabetic, the A1C test can tell you if you are at risk of developing it.

How does A1C testing help diabetes control?

If you have diabetes, the A1C test can help you manage it by confirming your self-testing results and helping you gauge whether your treatment and lifestyle plan are working or if adjustments are required.

How does it work?

Hemoglobin, a protein that links with glucose (blood sugar), is found inside your red blood cells. Its job is to carry oxygen from the lungs to all of the cells in your body. Extra glucose in your body enters your red blood cells and links with molecules of hemoglobin. By measuring the percentage of A1C in the blood, you get an overview of your average blood glucose over time.

How does the A1C test look backward?

A red blood cell lives 90-120 days and is replaced by fresh red blood cells, which are made in your bones. The amount of A1C in your blood reflects blood sugar control for the past 120 days, or the lifespan of a red blood cell.

An A1C test result between 5.7 and 6.4 percent indicates pre-diabetes and an A1C level of 6.5 percent or higher indicates diabetes. If you discover you are pre-diabetic, immediate lifestyle changes can help you to keep the number below the diabetic range. If your level is 6.5 or higher you will begin treatment for diabetes. To watch your overall glucose control, your doctor should measure your A1C level at intervals every 6 months or more, depending upon your risk factor. Although the A1C test is an important tool, it can't replace daily self-testing of blood glucose for those who are diabetic.