Health
Fact-checked

At WiseGEEK, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What is A1c?

Koren Allen
Koren Allen

A1c, also called hemoglobin A1c, is a blood test that measures the level of glycosolated hemoglobin in a person's blood. This is a common test ordered for people with diabetes or people suspected of having diabetes. It gives the doctor an idea of a person's average blood sugar, or blood glucose levels, over the prior three to four months. It does not replace daily blood glucose monitoring, but in combination with daily readings, the test helps the doctor determine how well a current diabetes treatment plan is working.

Glycosolated hemoglobin is found in everyone's blood in small amounts. It is a compound that forms when glucose molecules bond with hemoglobin, or red blood cells. Once this bond is formed, it does not break down, but remains in the bloodstream. Hemoglobin cells live for approximately 120 days, so at the time the test is performed, it will measure the amount of hemoglobin that has attached to glucose over the last three to four months. When more glucose is in the blood, more A1c is formed, so elevated levels of A1c indicate that daily blood glucose levels have also been elevated over this time period.

The A1c test enables a doctor to determine how well a diabetes treatment plan is working.
The A1c test enables a doctor to determine how well a diabetes treatment plan is working.

Diabetes treatment plans strive to keep a patient's blood sugar within normal limits and reduce the risks associated with high blood sugar, which include blindness, kidney damage, and nerve damage in the arms and legs. Daily blood glucose readings will give the patient an immediate idea of his blood glucose levels, which helps the patient make immediate corrections in diet or medication, as directed by their doctor. In addition to daily monitoring, doctors use the test to get an overview of how well the current treatment plan is working. It may help a doctor decide whether a patient needs insulin and how much is needed. If a doctor suspects diabetes in a patient who has not yet been diagnosed, the test is sometimes used as a diagnostic tool, indicating whether the patient has had elevated blood glucose over the prior three to four months.

A1c can be used in conjunction with blood glucose monitoring.
A1c can be used in conjunction with blood glucose monitoring.

Scientists discovered the A1c compound in 1967, and the American Diabetes Association, or ADA, began recommending routine testing of A1c levels for diabetic patients in 1988. In a person without diabetes, the normal range of A1c in the blood is 4-6%. Levels above 7% indicate that a current treatment plan may not be working effectively. The ADA recommends testing levels every four months for diabetic patients who use insulin, and every two months for diabetic patients who are not using insulin. Your doctor will use this and other tests to determine the treatment plan that is best for you.

Discussion Comments

anon944467

@anon944318: Good grief. Most doctors I know love it if their diabetic patients can come off their meds, and some are able to do so. They are able to control their disease with diet and exercise, and every person I know who is able to do that (and I know a few) has a doctor who supports that fully.

Some blood pressure medications can cause elevated blood glucose levels, but ACE inhibitors don't. In fact, they help prevent kidney damage. Metformin doesn't damage kidneys, either.

If you want to get all indignant, go after the insurance companies that have opted not to cover weight loss surgery, which for obese diabetics, can amount to long-term remission. No more medication, ever. Why don't you get worked up about that?

I wish like hell there was a cure for diabetes, but saying my doctor wants to keep me sick is a load of crap. It just is. If she wants to keep me sick, why is she so pleased when my bloodwork, including kidney function, is normal and when my blood pressure is normal?

Are you diabetic? Do you know what it's like to deal with this on a daily basis? Are you trying to get off these "deadly medications?" If they're so deadly, why are diabetics who are compliant and managing their disease living decades longer than they did just 60 years ago without medications? If you're not diabetic, then please, let those of us who are manage our conditions in peace without having to listen to people who aren't even diabetic tell us what we're doing wrong. We get enough crap from the media telling us we're morally deficient because we have the disease to begin with. We don't need laymen yowling at us too.

anon944318

What about doctors finding a plan to get you off these deadly medications? These medications can lead to kidney failure as well, so be honest about it. I found out blood pressure medicines can cause sugar levels to go up, and cause type 2 diabetes. What is wrong with you guys, especially knowing that doctors are not trying to get your health become back to normal? They are just trying to keep you on medications. I have never seen so many sick people in my entire life in America as now.

Rotergirl

The A1c is the ultimate judge and jury. It cannot be faked. A diabetic can fudge the numbers on the meter for his doctor, but the A1c tells the true story, every time. It cannot be fooled.

There are some exceptions that can affect the A1c, that the doctor will understand: a virus or other infection will often run a diabetic's blood sugar through the roof, so that can affect the readings. Also, taking prednisone can cause elevated blood sugar in some people, so that's another reason for an elevated A1c. A diabetic can have good numbers 90 percent of the time, but a week on prednisone or a round with a cold or flu can cause the A1c results to be a little skewed.

So, unless you've been ill or on steroids, your A1c will tattle on you every time if you've been naughty.

Post your comments
Login:
Forgot password?
Register:
    • The A1c test enables a doctor to determine how well a diabetes treatment plan is working.
      By: Edyta Pawlowska
      The A1c test enables a doctor to determine how well a diabetes treatment plan is working.
    • A1c can be used in conjunction with blood glucose monitoring.
      By: charger_v8
      A1c can be used in conjunction with blood glucose monitoring.
    • The A1C test is designed to average blood sugars over a period of a few months.
      By: Tim UR
      The A1C test is designed to average blood sugars over a period of a few months.
    • Prolonged high blood sugar may cause vision problems in diabetics.
      By: JackF
      Prolonged high blood sugar may cause vision problems in diabetics.
    • Blood glucose readings allow patients to receive feedback and make necessary changes to their medication.
      By: brankatekic
      Blood glucose readings allow patients to receive feedback and make necessary changes to their medication.