Can Blood Sugar Be Normal but HbA1c High?

It is possible to have blood sugar readings that appear normal while simultaneously having a high HbA1c level. This can lead to questions, especially if blood sugar levels are monitored regularly. HbA1c, or hemoglobin A1c, provides an overview of average blood sugar levels over the past two to three months, while blood sugar readings offer a snapshot in time. The two measurements can sometimes seem to present different information.

Key takeaways

HbA1c reflects average blood sugar over several months.
Blood sugar readings show levels at a specific moment.
Factors like timing of tests and individual variations can cause differences.
HbA1c can be high even with normal daily readings.
This doesn’t always indicate a problem, but it warrants discussion with a healthcare provider.
Other health conditions can also influence HbA1c.
Diet and exercise can impact both blood sugar and HbA1c.
Regular check-ups are important for understanding overall health.

Why this happens

The discrepancy between normal blood sugar readings and a high HbA1c often relates to the different ways these two measurements work. Consider it analogous to traffic. Blood sugar readings are like real-time traffic updates – what is happening at this moment. HbA1c is like looking at the overall congestion on the roads over a period of time. Even if roads appear clear at the moment of checking, there may have been detours and delays earlier that day or week that affected average travel time.

HbA1c measures the percentage of red blood cells that have glucose attached. This attachment happens over time, reflecting the average amount of glucose in the blood. If blood sugar levels are frequently elevated, even if they return to normal at other times, HbA1c will likely be higher. The HbA1c test essentially provides a historical perspective on blood sugar levels.

Real-world scenarios

A common situation involves checking blood sugar first thing in the morning, with a reading within a normal range. However, higher blood sugar levels may have been experienced after meals throughout the day. This pattern might not be obvious from a single reading but would be reflected in a higher HbA1c. Another example involves someone who monitors blood sugar and sees normal readings most of the time. However, occasional spikes might be experienced due to stress or illness. These spikes, even if infrequent, can still contribute to a higher HbA1c.

For example, imagine traveling and having a flight to catch. The departure board shows the flight is on time (normal blood sugar reading). However, delays might have been experienced getting to the airport (elevated blood sugar) or a longer wait at security (stress-related blood sugar spike). Even though the flight itself is on time, the overall travel experience might have been more complicated than it seemed initially.

Risk factors and what may help

Symptoms and early signs

Often, there are no noticeable symptoms in the early stages. However, as HbA1c levels rise, some may experience increased thirst, frequent urination, fatigue, blurred vision, or slow-healing sores. These symptoms are not always present, and their absence doesn’t necessarily mean there is no issue. The best approach is through regular check-ups and discussions with a healthcare provider.

How it’s checked

HbA1c is measured through a blood test. The test can be done at a doctor’s office or a lab. Fasting is typically not required before the test. Results are usually available within a few days. Blood sugar levels are often measured using a finger-prick test with a glucose meter or through continuous glucose monitoring (CGM) devices.

What this means in everyday life

If normal blood sugar readings are present but HbA1c is high, it can indicate that blood sugar levels are fluctuating throughout the day. This could mean that blood sugar is elevated after meals or at other times. It’s important to understand that a high HbA1c, even with normal readings, may suggest an increased risk of developing diabetes-related complications over time. Discussing these results with a healthcare provider is important to determine the best course of action.

Red flags: when to seek medical advice

If any symptoms of high blood sugar are noticed, such as increased thirst, frequent urination, or blurred vision, consulting with a healthcare provider is important. Additionally, if HbA1c is consistently high, even with normal blood sugar readings, discussing this with a doctor is essential. They can help understand the underlying causes and recommend appropriate steps.

Why people get confused

People often get confused because they expect the two measurements to align perfectly. They might see normal blood sugar readings and assume overall blood sugar control is excellent. However, HbA1c provides a different perspective. It’s like looking at the average speed of a car over a long journey. Even if the car is currently traveling at a normal speed, it might have been going much faster or slower at other points in the trip, affecting the overall average.

Here’s the part most people miss:

The key thing many people overlook is the impact of timing. A person might check blood sugar first thing in the morning and get a normal reading. However, they might not realize that blood sugar spiked after dinner the night before. This spike, even if it returned to normal later, can still influence the HbA1c result. Considering the entire day’s blood sugar fluctuations, not just the readings at a single point in time, is important. This is where tools like continuous glucose monitors (CGMs) can be helpful, as they provide a more complete picture of blood sugar patterns throughout the day.

Questions to ask your healthcare provider

What is my HbA1c level, and what does it mean?
What factors might be contributing to the difference between my blood sugar readings and my HbA1c?
Are there any lifestyle changes that could be considered to improve blood sugar control?
Do I need any additional tests or monitoring?
What are the potential risks associated with a high HbA1c?

Frequently asked questions

How is HbA1c commonly discussed in relation to diabetes?
What is known about the relationship between HbA1c and blood sugar levels?
Why do people associate HbA1c with long-term blood sugar control?
What does research suggest about the accuracy of HbA1c testing?
How is continuous glucose monitoring (CGM) being explored in diabetes care?

Label scanner: what to check in 10 seconds

Serving size: Check the amount of food the nutrition information is based on.
Total carbohydrates: Note the total grams of carbohydrates per serving.
Added sugars: Look for the amount of added sugars, which can include syrups.
Ingredients list: Scan for ingredients like maltodextrin and dextrose.
Fiber: Fiber can help slow down the absorption of sugar.

References

American Diabetes Association (ADA)
Centers for Disease Control and Prevention (CDC)
World Health Organization (WHO)
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Mayo Clinic
Cleveland Clinic

The information provided in this article is intended for general knowledge and informational purposes only, and does not constitute medical advice. It is essential to consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Consider discussing with your doctor if Lifebetic might be an option for you.