Hemoglobin A1c Test Popular

The Hemoglobin A1C test evaluates the average amount of glucose in the blood over an 8-12 week time span.

Known as the hemoglobin A1C test or HbA1C test, other names for the test include the glycosylated hemoglobin test, glycohemoglobin test, glycated hemoglobin test, or A1C.

This test is recommended by the American Diabetes Association, the European Association for the Study of Diabetes, and the International Diabetes Federation. It is the primary test used to diagnose prediabetes, type 1 and type 2 diabetes, and to monitor how well you are managing your diabetes.

How does the Hemoglobin A1C test work?

The glycated hemoglobin (A1C) blood test measures how thick the coat of glucose is that is bound to the blood's hemoglobin (or blood sugar levels). When the two bind, the hemoglobin gets a coat of sugar around it. The coat thickens as the amount of glucose in the blood increases. The hemoglobin A1C test measures for HbA1C, a subtype of hemoglobin.

Hemoglobin is a protein found inside the red blood cells (RBCs), and its main job is to transport oxygen. It also is responsible for giving blood its red color. There are multiple types of hemoglobin, but its main form is hemoglobin A. Glucose spontaneously binds to hemoglobin as it circulates the blood, this is called glycated hemoglobin, and its predominant form is referred to as A1C. When glucose binds to the hemoglobin, it’s there for the entire life of the red blood cell (usually about four months). The more glucose that’s in the blood, the more glycated hemoglobin is created. A1C is produced on a daily basis and additionally, it dies on a daily basis as older RBCs die and are replaced with younger RBCs that have not yet been affected by glucose.

How often should a diabetic take this test?

After a diabetes diagnosis, this test is often recommended four times per year if glycemic goals are not met. If the glycemic control is stable, then twice per year. Those with diabetes often must take extra care to keep their glucose levels as close to normal as possible. Chronically high glucose levels lead to problems like damage to the kidneys, eyes, cardiovascular system, and nerves. 

What are the symptoms and risks of diabetes?

Some symptoms of diabetes include:

• Frequent urination
• Increased thirst or a dry mouth
• Unexpected weight loss
• Constant hunger
• Foot pain or numbness
• Frequent infections
• Blurred vision

How does lab testing differ from at-home methods?

In the past, those with diabetes had to depend on urine tests or a daily finger prick to monitor blood sugar levels. This, unfortunately, only monitored blood sugar in the moment, which can actually fluctuate quite a bit throughout the day. Meaning, if you had high blood sugar in the middle of the night, the odds of you knowing were pretty low.

The A1C test was made available to the public in the 1980's and is now a very important tool in diabetes control. As this test measures your glucose levels over a three-month time span, it can give you a better overall idea of how high your glucose actually is, rather than a snapshot glimpse.

Interpreting your Hemoglobin A1C test results

Non-diabetics will have an A1C result of less than 5.7%, while a diabetic will often have an A1C level of 6.5 or higher. Anyone between 5.7% and 6.4% is at increased risk of diabetes later in life (or prediabetes,) and should talk to their healthcare provider.

It’s important to work with a healthcare provider to determine what your body needs: usually, a mix of diet control, exercise, and medication will effectively stabilize your glucose or A1C levels.