Understanding Freestyle Libre: Freestyle Libre False Low Readings [Reasons And Solutions]

For individuals with diabetes, the Freestyle Libre continuous glucose monitoring (CGM) system has been a game-changer, offering real-time insights into blood sugar levels without the need for frequent fingerstick tests. 

However, like any technology, it’s not without its quirks, and one of the common challenges users encounter is false low readings. 

These readings can be concerning and potentially lead to unnecessary interventions, affecting diabetes management.

In this blog post, we’ll delve into the world of Freestyle Libre’s false low readings, exploring the various factors that can cause them. 

We’ll also provide practical solutions to help minimize the occurrence of these inaccuracies, ensuring that your CGM experience remains as reliable and helpful as possible. 

Whether you’re new to the Freestyle Libre system or a seasoned user, understanding and addressing false low readings is crucial for effective diabetes care. Stay focused. 

What Is Freestyle Libre?

The Freestyle Libre is a continuous glucose monitoring (CGM) system designed to help individuals with diabetes manage their blood sugar levels more effectively. 

Developed by Abbott Laboratories, this device consists of a small sensor that is placed on the skin’s surface, typically on the upper arm. 

The sensor continuously measures glucose levels in the interstitial fluid beneath the skin, providing real-time data without the need for routine fingerstick blood tests.

Users can easily scan the sensor with a handheld reader or a smartphone app to obtain instant glucose readings, historical data, and trends. 

This technology offers a more convenient alternative to traditional blood glucose monitoring methods, allowing individuals with diabetes to make decisions about their diet, insulin dosages, and overall management. 

Freestyle Libre has significantly improved the quality of life for many people with diabetes by providing greater insight into their blood sugar control.

Functions of Freestyle Libre 

The Freestyle Libre system offers several key functions to assist individuals with diabetes in managing their blood sugar levels:

Continuous Glucose Monitoring (CGM)

Freestyle Libre provides continuous, real-time monitoring of glucose levels. The sensor records glucose data at regular intervals, usually every few minutes, and stores this information for easy access.

Trend Analysis

Users can view trends in their glucose levels over time. This allows for a better understanding of how their blood sugar changes throughout the day, helping them identify patterns in their diabetes management.

Glucose Readings

The system offers on-demand glucose readings by scanning the sensor with a handheld reader or smartphone app. 

This eliminates the need for frequent fingerstick blood tests, making it more convenient and less invasive.

Historical Data

Freestyle Libre stores historical glucose data, allowing users to review their past readings and track changes in their blood sugar levels over days, weeks, or even months.

Alarms and Alerts

Users can set customizable high and low-glucose level alerts to receive notifications when their blood sugar goes out of their target range. 

This feature helps in proactive management and early intervention to prevent extreme highs or lows.

Insulin Dose Adjustments

With real-time glucose information readily available, individuals can make more accurate decisions about their insulin dosages, reducing the risk of hypoglycemia (low blood sugar) or hyperglycemia (high blood sugar).

Mealtime Assistance

Freestyle Libre can provide insights into how different foods affect blood sugar levels, helping users make informed choices about meal planning and carbohydrate intake.

Convenience

The sensor is easy to apply and wear, typically lasting up to 14 days, providing continuous monitoring without the need for daily sensor changes.

Freestyle Libre enhances diabetes management by offering comprehensive glucose data, ultimately helping individuals with diabetes achieve better control of their condition and improve their quality of life.

Is Freestyle Libre’s Read Accurate?

The Freestyle Libre system is generally considered to provide accurate glucose readings. 

However, like any continuous glucose monitoring (CGM) system, there can be occasional discrepancies between the CGM readings and traditional fingerstick blood glucose measurements.

Several factors can influence the accuracy of CGM systems, including the Freestyle Libre:

Calibration

Unlike some other CGM systems, the Freestyle Libre does not require routine fingerstick calibration. Instead, it is factory-calibrated, which means that it should provide accurate readings without user-initiated calibration. 

However, it’s essential to apply the sensor correctly and follow the manufacturer’s instructions for optimal performance.

Sensor Placement

Proper sensor placement is crucial for accuracy. If the sensor is not placed correctly on the skin or if there are issues with adhesion, it can lead to inaccurate readings.

Lag Time

CGM systems, including Freestyle Libre, may have a slight lag time compared to real-time blood glucose levels. This lag is generally minimal but can vary from person to person.

Interstitial Fluid

CGM systems measure glucose levels in interstitial fluid, which may not always precisely match blood glucose levels. There can be a time delay and variations between interstitial fluid and blood glucose.

User Factors

Individual factors such as skin temperature, hydration, and body movement can affect CGM accuracy.

The Freestyle Libre is considered a reliable and accurate CGM system for many individuals with diabetes. 

Reasons for Freestyle Libre’s False Low Readings

While the Freestyle Libre system is generally accurate, there are instances where it might produce false low readings. 

Several factors can contribute to false low readings in continuous glucose monitoring (CGM) systems like Freestyle Libre. Here are some common reasons:

Compression at the Sensor Site

Pressure on the sensor due to sleeping or lying on it, wearing tight clothing, or applying adhesive too tightly can cause compression of the tissue under the sensor. 

This can restrict blood flow to the interstitial fluid, leading to false low readings.

Sensor Placement Errors

If the sensor is not correctly placed on the skin, it can lead to inaccurate readings. Ensuring proper sensor placement, as per the manufacturer’s instructions, is crucial for accurate results.

Interference with Sensor

Certain substances or conditions can interfere with the sensor’s function, potentially causing false low readings. These might include alcohol swabs, skin creams, or even excessive sweating.

Sensor Age and Wear

As the sensor gets closer to the end of its wear period (usually around 14 days), it may become less accurate, leading to false low readings. Sensor wear time should not be exceeded.

Calibration Issues

Freestyle Libre does not require calibration by the user, as it is factory-calibrated. 

However, if there are issues with the factory calibration or the sensor’s initialization process, it could lead to inaccurate readings.

Hypoglycemia Lag

CGM systems, including Freestyle Libre, can sometimes lag behind real-time blood glucose levels, especially during rapid glucose changes. This can result in false low readings when glucose levels are dropping quickly.

Sensor Signal Interruptions

Anything that disrupts the signal between the sensor and the reader (e.g., electromagnetic interference, distance from the reader) can lead to false readings.

Sensor Aging

Over time, the sensor’s performance may degrade, resulting in less accurate readings.

It’s important to note that while false low readings can occur, CGM systems like Freestyle Libre have improved diabetes management for many individuals. 

Users should be aware of these potential issues, follow proper sensor placement and maintenance guidelines, and consult with their healthcare providers to interpret and act on CGM data accurately.

How to Identify False Low Readings on Freestyle Libre?

Identifying false low readings on the Freestyle Libre or any continuous glucose monitoring (CGM) system is important for accurate diabetes management. 

Here are steps to help you recognize and address potential false low readings:

Symptoms

If you are experiencing symptoms of hypoglycemia, such as shakiness, sweating, dizziness, confusion, or hunger, but your CGM reading shows a low value and you don’t feel these symptoms, it may be a false low reading.

Check for Trends

Examine the trend in your CGM data. If you see a sudden drop in your glucose level followed by a rapid rise back to your target range, it could be a sign of a false low reading.

Sensor Age

Consider how long the sensor has been in use. As sensors age, they may become less accurate, which can result in false readings. 

If you’re nearing the end of the sensor’s wear period (usually around 14 days), be more cautious about interpreting low readings.

Verify with Fingerstick Test

When in doubt or if you suspect a false low reading, perform a fingerstick blood glucose test using a traditional blood glucose meter. 

Compare the CGM reading to the fingerstick reading to confirm the accuracy. If the fingerstick reading is significantly higher than the CGM reading, it’s likely a false low reading.

Consider External Factors

Think about any external factors that may have influenced the CGM reading. 

For example, if you applied pressure to the sensor site or had a recent meal or physical activity, these factors could lead to temporary discrepancies in the readings.

Calibration Check

Freestyle Libre does not require user calibration, but you can ensure that the sensor initialization process is completed correctly when starting a new sensor.

Data Consistency

Look at the overall consistency of your CGM data. If you notice frequent, sudden drops to low readings that do not align with your usual patterns, it may indicate a sensor issue.

Consult Your Healthcare Provider

If you have concerns about the accuracy of your CGM readings or are unsure whether a reading is accurate, consult your healthcare provider or diabetes care team. They can provide guidance and help troubleshoot any issues.

Remember that CGM systems, like Freestyle Libre, are valuable tools for diabetes management but may occasionally produce false readings.

Solutions to Minimize False Low Readings on Freestyle Libre

Minimizing false low readings on the Freestyle Libre or any continuous glucose monitoring (CGM) system is crucial for effective diabetes management. Here are some solutions to help reduce the occurrence of false low readings:

Proper Sensor Placement

Ensure that you follow the manufacturer’s guidelines for sensor placement. Correct placement is critical for accurate readings. 

Avoid areas with a lot of muscle movement or places where the sensor may be subjected to excessive pressure.

Skin Preparation

Clean the sensor site with soap and water and allow it to dry thoroughly before applying the sensor. Avoid using alcohol-based products, as they can interfere with sensor accuracy.

Avoid Compression

Be mindful of activities or positions that may compress the sensor site, such as sleeping on your sensor or wearing tight clothing. 

This compression can lead to false low readings. Experiment with sensor placement locations to find a spotless prone to compression.

Stay Hydrated

Dehydration can affect the interstitial fluid and may lead to inaccurate readings. Ensure you are well-hydrated to help maintain consistent readings.

Calibration Check

While Freestyle Libre does not require user calibration, make sure you follow the sensor initialization process correctly when starting a new sensor. Confirm that the initialization was successful.

Check Sensor Age

Keep track of how long the sensor has been in use. Sensors can become less accurate as they approach the end of their wear period. Replace the sensor if you suspect accuracy issues.

Verify with Fingerstick Tests

If you are uncertain about a low reading, perform a fingerstick blood glucose test using a traditional glucose meter to confirm the reading. 

Compare the CGM reading to the fingerstick result and take appropriate action based on the more accurate reading.

Address Interference

Be aware of substances or activities that can interfere with the sensor’s function, such as exposure to electromagnetic fields or contact with creams or ointments. Minimize exposure to such factors.

Consult Your Healthcare Provider

If you continue to experience false low readings despite following these steps, consult your healthcare provider or diabetes care team. 

They can help troubleshoot the issue and may recommend specific adjustments or interventions.

Maintain Sensor Adhesion

Ensure the sensor adhesive remains intact throughout its wear period. You can use additional tape or adhesive products if needed to secure the sensor in place.

By implementing these solutions and being proactive in managing your CGM system, you can reduce the occurrence of false low readings and rely on more accurate data to make informed decisions about your diabetes management.

FAQs 

Why am I getting false low readings on my Freestyle Libre?

False low readings on the Freestyle Libre can occur due to factors like sensor compression, incorrect placement, external interference, or sensor aging. 

These issues can momentarily affect interstitial fluid glucose levels, leading to inaccurate readings.

How can I confirm if a low reading on my Freestyle Libre is false?

To confirm a low reading, perform a fingerstick blood glucose test using a traditional meter. If the fingerstick reading is significantly higher than the CGM reading, it suggests a false low reading on your Freestyle Libre.

Can dehydration cause false low readings on Freestyle Libre?

Yes, dehydration can impact interstitial fluid glucose levels, potentially causing false low readings. It’s important to stay well-hydrated to minimize this effect and maintain CGM accuracy.

Is Freestyle Libre more prone to false low readings as the sensor gets older?

Yes, CGM sensors, including Freestyle Libre, may become less accurate as they approach the end of their wear period (around 14 days). 

This sensor aging can contribute to false low readings, and it’s advisable to replace the sensor if accuracy issues arise.

What should I do if I consistently experience false low readings on Freestyle Libre?

If you consistently encounter false low readings despite proper sensor care, consult your healthcare provider or diabetes care team. 

They can help troubleshoot the issue, offer personalized guidance, and determine if any specific adjustments or interventions are needed for your situation.

Wrapping Up

False low readings on the Freestyle Libre can be frustrating and worrisome, but armed with knowledge and proactive steps, you can navigate this challenge successfully. 

Remember, CGM technology, while remarkable, has its limitations. Regularly verifying readings with fingerstick tests and following proper sensor care practices can significantly reduce the chances of encountering false lows. 

If issues persist, consulting your healthcare provider or diabetes care team is a wise step to ensure optimal CGM performance. 

By staying informed and proactive, you can continue to enjoy the benefits of Freestyle Libre while minimizing the impact of false low readings on your diabetes management journey. Thank you.