Written on August 9, 2023 by Sendra Yang, PharmD, MBA. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.
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If you don’t have diabetes, you may probably know someone who does. Diabetes is one of the most common chronic diseases in the United States. Over 37 million Americans have diabetes, and around 98 million have prediabetes. With more people becoming overweight or obese, the number of diagnosed diabetes has more than doubled in the past 20 years. In the United States, diabetes is the eighth leading cause of death. A powerful test called the HbA1c, or A1c, can help identify prediabetes and diagnose diabetes. Learn more about what the HbA1c is, the best time for HbA1c, and answers to other common questions regarding the test.
HbA1c is also known as hemoglobin A1c, glycated hemoglobin, or A1c. The HbA1c test is used to evaluate how well you are controlling your glucose or sugar levels. The test can also help diagnose diabetes. The HbA1c is reported as a percentage result and represents an average of your blood sugar levels over the past three months.
Hemoglobin is a protein that functions mainly to carry oxygen in red blood cells. Hemoglobin bound to oxygen is what gives your blood its bright red color. Glucose in the bloodstream can become attached to hemoglobin; glycated hemoglobin is the medical term describing hemoglobin linked to glucose.
The HbA1c measures the average amount of glycated hemoglobin in your blood over a period of 3 months. The lifespan of a red blood cell is around three months, and the test reflects the percentage of red blood cells with glucose-linked hemoglobin present at the time of the blood draw. The more glucose you have in your bloodstream, the more glycated hemoglobin you will have, yielding a higher HbA1c result.
The HbA1c test does not require you to fast before having your blood drawn. Typically, tests that require you to fast are drawn in the mornings after not eating overnight and before you eat for the day. But you can take the HbA1c test at any time of the day.[4,5]
How often you should get the test and when can vary depending on whether you are testing to identify diabetes and prediabetes or managing the disease after your diagnosis. If you have diabetes, get an HbA1c test at least two times a year and more often if there are changes to your medications. If you don’t currently have diabetes or prediabetes and are over 45 years of age, have risk factors, or have had gestational diabetes in the past, get the HbA1c test every three years. If you have prediabetes, speak with your healthcare provider about ways to improve your health and lower your risk of diabetes. Repeat your HbA1c every one to two years or as your healthcare provider recommends. If you don’t show symptoms of prediabetes or diabetes, but your result shows otherwise, get a second test done on a different day. Speak with your healthcare provider about how often you should get tested and the best time for HbA1c testing.
The HbA1c can be done in a lab through a traditional blood draw or with a finger stick. It may take a few days to get the results back from a lab. During the blood collection process, you can expect the following:
If a finger stick was completed in your doctor’s office, you could get a result in about 5 minutes. When getting a finger stick, you can expect the following :
At Everlywell, there is also an option for an HbA1c at-home lab test. When you receive your test kit, you can register it online. Then you can collect your sample from the comfort of your own home and mail it to a certified lab for testing. You will receive your results on a secure platform within a few days.