Understanding the Difference Between HbA1c and Blood Glucose

Man Checking His Glucose Levels

Back in the Middle Ages, doctors used a method called uroscopy—diagnosing illnesses by tasting urine. Surprisingly, they actually got one right: diabetes, thanks to the sweet taste. By the 18th and 19th centuries, ants took over the role of diagnosis, being drawn to the sugar in urine—a telltale sign of the condition we now recognize as diabetes. We’ve come a long way since the early days of diabetes detection. Fast forward to the 20th century, chemical methods for detecting sugar in urine and whole blood samples became the norm, solidifying hyperglycemia—excessive glucose in the bloodstream—as the primary diagnostic criteria for diabetes.


For decades since then, blood glucose levels were the “gold standard” for diabetes testing, with patients receiving recommendations to fast before screenings. However, a significant advancement arrived post-2010: The International Expert Committee recommended the use of Hemoglobin A1c (HbA1c) as a valuable diagnostic tool for diabetes. This blood test reflects your average blood sugar (glucose) level over the past two to three months. Since then, HbA1c testing has become a popular method for assessing long-term blood glucose control, unseating blood glucose from its position as a favorite among providers.


What’s a Healthy Blood Sugar Level?

For people living with diabetes, maintaining healthy blood sugar levels is crucial for managing the condition. According to the American Diabetes Association (ADA), the recommended blood glucose targets for most adults (who are not pregnant) are:


      • Before meals: 80 to 130 mg/dL
      • 1 to 2 hours after starting a meal: Below 180 mg/dL

These guidelines help individuals understand target blood sugar levels throughout the day. The ADA recommends following up with your doctor if your fasting glucose is 100 mg/dL or higher, or if your non-fasting glucose is 140 mg/dL or higher, especially if you’re experiencing symptoms such as increased urination, thirst, blurred vision, or unexplained weight loss.


The Key Differences Between Blood Glucose and A1c

Unless diagnosed with diabetes, most people typically only measure their blood glucose levels during their annual exam or through wellness programs like biometric health screenings offered by their employers. Blood glucose tests can provide valuable insights into a person’s immediate health, helping to identify potential prediabetes or diabetes risks.


Once identified, monitoring your blood glucose daily becomes essential. This gives individuals with diabetes an immediate snapshot of how various factors—such as diet, exercise, and stress—affect their blood sugar levels in real time. According to the Centers for Disease Control and Prevention (CDC), keeping track of these daily fluctuations is key to managing diabetes effectively.


However, HbA1c testing offers a different kind of insight. While blood glucose testing provides a snapshot, HbA1c provides the bigger picture—a running average of blood sugar levels over the past two to three months that is not fasting dependent for accuracy. This gives individuals and healthcare providers a more comprehensive view of how well diabetes is being managed over time, rather than just moment-to-moment.


What’s a Healthy Hemoglobin A1c Level?

For individuals managing diabetes, the general goal is to keep HbA1c levels below 7%, as recommended by the ADA. Because HbA1c reflects a longer period of blood glucose levels, it’s not necessary to measure it daily. Most people with well-controlled diabetes get their HbA1c tested two times per year.


Here’s how the ADA classifies HbA1c levels:


      • Normal: Below 5.7%
      • Prediabetes: 5.7% to 6.4%
      • Diabetes: 6.5% or higher

By using both daily blood glucose readings and periodic A1c tests, individuals and their healthcare providers can better tailor diabetes management plans to ensure long-term health.


Tips for Identifying Diabetes and Maintaining Healthy Blood Sugar and HbA1c Levels

So, your blood test has come back with elevated A1c or blood glucose levels. What should you do to ensure that you are staying on top of your health? Here are three simple tips:


      • Check: Be proactive with your health. Make sure to stay on top of your annual wellness exams or participate in company-offered health screenings. These tests often help identify prediabetes, giving you the opportunity to make lifestyle changes before it progresses.
      • Change: Type 2 diabetes can often be managed—and even reversed—with lifestyle changes. Talk to your doctor about what works for you. One simple change? Get 10 to 15 minutes of movement after every meal. This is especially important after larger meals, as it can prevent your blood sugar from spiking.
      • Consistency: If you’re struggling to keep your blood sugar within healthy ranges, it’s time to seek professional help. A healthcare provider or diabetes educator can create a customized plan to help you stay on track.

Both blood glucose and HbA1c are essential tools for understanding the risk of diabetes and or managing diabetes. Blood glucose screenings help you manage your levels on a daily basis, while HbA1c provides a long-term view of your blood sugar control. Together, these measures can help you monitor progress for those at risk or with diabetes to keep the system in check and live a healthier life. eHealthScreenings offers convenient options for blood glucose and HbA1c screenings via onsite workplace (finger stick or venipuncture), offsite lab, physician screening and at home test kit. Contact us, to learn more about our blood glucose and HbA1c options.