Glycated hemoglobin, or A1C, is a medical blood test result used to gauge how much glucose has been in a person’s blood over a three-month period. It’s usually preferred to a simple fasting blood glucose level since it reflects an average of the ups and downs of blood glucose levels over a longer time horizon. You can find our primer on normal blood glucose levels here.
What is A1C, and How is it Measured?
Hemoglobin is a molecule found within red blood cells that helps carry oxygen all around our body for cells to use. One unique property of this molecule is it can spontaneously bind to glucose, fructose, and galactose. Since red blood cells tend to live for around 120 days, we can measure the percentage of glucose that’s been bound to hemoglobin, or glycated hemoglobin. You can get this lab tested at any doctor’s office and at many larger pharmacy chains.
The best practice for interpreting your A1C result is always to discuss it with your primary care provider. This will provide the most context for your specific situation and goals. Here you can find what are generally considered normal levels of A1C and levels that you may want to take a closer look at.
Normal Levels of A1C
The normal range of A1C should be below 5.7%.
Prediabetic Levels of A1C
If your A1C levels are above 5.7%, then they’re above what’s considered normal. However, if they’re below 6.4%, this would still be regarded as a prediabetic range and not diabetes.
Diabetic Levels of A1C
Lastly, if your A1C levels are above 6.4%, this would be considered a marker of diabetes. Persistently elevated blood glucose levels have many adverse health effects. In this case, you should inform your primary care provider of this result as soon as possible.
Reasons to Order an A1C Test
Historically, this blood test has only been performed in the context of diabetes screening and workup. Today, you can always order an at-home test if you’re concerned and want an immediate result from a private laboratory. Alternatively, you can use an at-home test if you’ve been diagnosed with pre-diabetes and want to keep a close eye on your blood glucose trends. If you have symptoms that suggest you may be at risk of pre-diabetes, you can also use such a test to screen yourself, preferably in consultation with your primary care provider. People with other auto-immune diseases may be at increased risk of type 1 diabetes mellitus, for example, and often undergo an A1C test at least once annually. If you want to see a more detailed picture of your daily glucose trends, you can also use our guide comparing glucose monitors to find the best one that will work well for you.
Limitations of A1C Testing
If your blood glucose levels are fluctuating dramatically, in the sense that they have many spikes and lows over a 24-hour period, an average glucose level (what A1c measures) wouldn’t be able to pick up the high’s and low’s. One individual could have the same A1C value as another, but one person could be having glucose spikes to 140 while another is having spikes to 200. Also, because the test relies on the percentage of hemoglobin that has been glycated, the presumption is that hemoglobin is held constant, and the glucose in the blood is what will push the value higher or lower. But in some cases, such as people with chronic anemia, these results can be misleading as they have less hemoglobin than the average person. Even with the same amount of glucose in the blood, their A1C values would be elevated and could appear to indicate pre-diabetes when they are otherwise metabolically healthy. Similarly, someone with an intravascular hemolytic condition would have red blood cells broken down within the blood, causing further inaccuracy. Other examples that could cause your A1C level to be falsely high or low include recent blood loss, smoking, or Vitamin B12 deficiency.
Common Signs and Symptoms That You Might Have a High A1C
It can be challenging to see if you have pre-diabetes since the symptoms are not specific and often confused with other common diseases or simply having a bad day. Some diseases manifest across multiple organ systems, like Cushing Syndrome, Polycystic Ovary Disease, or Hypothyroidism. In all these cases, as well as in Type 2 Diabetes Mellitus, you can have a finding called acanthosis nigricans, or the presence of darkened skin along the skin folds in the armpit, neck, or groin. Of course, not every presentation is the same. This can also be caused by extreme obesity, and some people also have skin tags growing along the patches of skin folds affected.
Ways to Lower Your A1C Levels
Keep an eye out for an upcoming comprehensive post on ways to control long-term glucose levels, but for the present moment, have a look at our short recommendations.
Exercise / Regular Physical Activity
In addition to improving insulin sensitivity, exercise can improve the metabolic handling of sugars in general. You can read more about this here.
Get Enough Sleep
Although this is an excellent wellness practice in general, it is imperative to get enough sleep if you are trying to keep blood glucose levels within a healthy range.
Acute stress is a normal part of life and some stress can actually be beneficial, but chronic stress is quite harmful to controlling blood glucose levels.
Engage with Your Blood Glucose Levels with Nutrisense
Your blood sugar levels can significantly impact how your body feels and functions. That’s why stable blood glucose levels can be an important factor in supporting overall wellbeing.
With Nutrisense, you’ll be able to track your blood glucose levels over time using a CGM, so you can make lifestyle choices that support healthy living.
Ready to take the first step? Start with our quiz to see how Nutrisense can support your health.
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Kara Collier is the co-founder and VP of Health at Nutrisense, one of America’s fastest-growing wellness-tech startups, where she leads the health team. She is a Forbes 30 under 30 recipient, frequent podcast guest & conference speaker.