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The FreeStyle Libre 3 Continuous Glucose Monitoring (CGM) system has been praised for its impressive accuracy with a staggering 7.9% MARD (mean absolute relative difference), even surpassing the FDA’s required parameters. Its 14-day sensor delivers reliable readings that help users manage their diabetes effectively. However, like any medical device, users may occasionally experience accuracy issues. Here are some potential causes and solutions for Freestyle Libre 3 accuracy problems.
Initial 24-Hour Adjustment Period
Whether you’re using the FreeStyle Libre 3, Libre 2, or even a Dexcom CGM, the first 24 hours after applying a new sensor can result in inconsistent readings. This occurs because:
- The sensor is acclimating to the subcutaneous environment.
- The body’s tissue may take time to adjust to the filament.
Solution: To minimize disruptions:
- Apply the new sensor on the opposite arm a day before your current sensor expires.
- Monitor closely during this period using fingerstick tests if necessary.
Common Sensor Issues and Their Remedies
1. Sensor Error Message
A “Sensor Error” message indicates the system’s inability to provide glucose readings. This could be due to:
- Calibration issues.
- External interference or incorrect sensor application.
What to Do:
- Tap the “i” information symbol on the app for specific instructions.
- Recheck after the suggested duration.
- If the issue persists, fill out the online sensor support request form or contact customer care at 855-632-8658.
2. Replace Sensor Message
This message may suggest a fault in the sensor. It typically occurs when the system detects an irreparable error.
What to Do:
- If 14 days have passed already, remove the sensor and start a new sensor.
- If this message appears before the 14-day wear period ends, claim a replacement sensor through Abbott’s support.
3. Readings That Don’t Match Symptoms
If your glucose readings don’t align with how you feel or your symptoms:
- Perform a fingerstick test to confirm your blood glucose levels.
- Cross-check the FreeStyle Libre 3 readings with a traditional blood glucose meter.
When to Seek Help:
If discrepancies persist, depending on the issue, consult Abbott’s customer support or your healthcare specialist.
Did you know?
Freestyle Libre 3 Plus Sensor is the same size as Freestyle Libre 3, offering 15 days of life and compatibility with some of the latest AID (automatic insulin delivery) systems.
Common CGM Accuracy Issues and Solutions
Many people are side sleepers and wear sensors on the same side. When pressure is applied to the CGM sensors, they tend to provide incorrect readings due to the compression. This needs to be taken care of, you may try changing the side of the sensor or simply change the side you sleep.
Moreover, loose sensors may fail to provide accurate readings or fall off altogether. You may use hypoallergenic and waterproof CGM patches to keep your CGM sensor intact and in place during physical activities, including swimming.
Is Your Faulty CGM Still Not Working Right?
No worries! If your sensor is faulty or inaccurate, don’t throw it away. Abbott offers free sensor replacements at no extra cost. Complete a Freestyle Libre sensor support request form to claim your new sensor delivered to your doorstep. Here is the link; https://www.freestyle.abbott/us-en/support/sensorsupportrequest.html
Extra Value Tip
Log in to LibreView using the same credentials as your phone app. It provides insights such as:
- A1c trends.
- Mealtime patterns.
- Daily glucose variations and trouble spots where the sensor struggled to capture data.
Share Your Data
With the Libre LinkUp app, users can share real-time glucose data with family or healthcare providers. This feature also sends alerts for high or low readings, ensuring prompt action in emergencies. The picture below shows all the steps to share your data on Freestyle Libre 3 sensors. You may follow the same steps to share data on Libre 2 and Libre 2 Plus as well.
Conclusion
While the FreeStyle Libre 3 sensor boasts high accuracy, occasional Freestyle Libre 3 accuracy problems may arise due to initial sensor adjustment, user error, or faulty hardware. However, there are troubleshooting steps you may follow to get rid of these errors, and in case they persist, you may always fill out a form to claim your new sensor. The link to the Freestyle Libre Sensor Support Request form has been provided above.
For reliable diabetic supplies, free deliveries (within the USA), easy re-ordering, and friendly customer support visit CGM Monitors today!
I have a problem with accuracy low alarm goes off and a finger stick shows 60-point difference, 3 sensors in a row have done this seems to work fine for 6 days then goes haywire. What am I doing wrong? I can call and they will send another sensor but that’s not fixing the problem.
Hello Robert. Sorry to hear about any inconvenience you may have experienced. Abnormal pressure on the sensor or loosened sensors, both can give inaccurate readings. It appears like your CGM sensors get loose after 6 days.
We recommend you try CGM patches once and check if your CGM sensors last longer than 6 days. You may use any other sensor stickers as well, based on your preference obviously.
i have using the free style libre 3 and sensor and reader for 3 days and the reading are way off i have been checking my blood sugar manually and they are not close to begin correct they are 60-70 points difference and the sensor ii alway going off stating my blood glucose is low or high emample tonight at bedtime manually was 235 a n the sensor was164
Hello Costella. Sorry to hear about any inconvenience you may have experienced. Here is why you may be seeing readings way off:
CGMs measure your glucose from interstitial blood whereas blood glucose meters measure it directly from your blood. Glucose levels in the blood change more rapidly than in the interstitial fluid. This creates a time lag, typically around 10-15 minutes, between BGM and CGM readings. The difference between BGM and CGM readings is most pronounced during periods of rapid glucose change, such as after meals, during and after exercise, or after taking insulin.
If you are not comparing the readings during these time spans and still seeing the big difference in readings, your sensor may have experienced compression, if not, your sensor may be faulty, and you need to contact Abbott customer support in this case. You can call them at 855-632-8658 between 8am to 8pm Eastern time (excluding holidays).
Hope this helps!
I have similar problem my sensor readings show low sugar after dinner though my blood test shows higher level difference of 20, so I end up eating which raises the sugar level to 200 or more during night
Hello Asha. Sorry to hear about any inconvenience you may have experienced due to this issue. Counting on your carbs is the key to managing your high blood sugar levels.
You may find it useful to check out your glucose trends after having your meals, specifically dinner, and then adjust your meal portions accordingly. If it’s a high carb meal (which you should avoid as you are experiencing high blood sugar), take it in a lesser quantity. Moreover, based on research we can see that some diabetic people find it useful to walk right after having their meals, and that controls their high blood sugar to a certain extent. I hope that helps!
This is the second sensor in a row that works and appears to be accurate but all history is lost.
The last one was on 2 weeks and always stayed connected but no history was stored or ever showed in app
Hey Gerald. Good to hear that your sensor is working accurately. To retrieve your glucose data, Log into your account at http://www.LibreView.com using the same login credentials that you use for the FreeStyle Libre 3 app*. From the “Glucose History” page, select “Download Glucose Data” and follow the steps to download your data.
I started using the FreeStyle Libre 3 about a month ago. Received two sensors to start. The first sensor failed with “Signal Loss” error after two days. Stopped bluetooth on the phone, stopped and restarted the App, and un-installed and installed the app. Nothing worked. Removed the sensor, installed a new one. It worked for two weeks. In the meantime, Abbott sent a replacement. When the second sensor timed out after 14 days, installed the one supplied directly from Abbott. It failed with the same error “Signal Loss” after 6 hours. Abbott sent another sensor as I had no more sensors to install. Installed it and it failed with the same error after 16 hours. The phone is on their acceptable list, bluetooth on the phone works, they have no suggestions other that a replacement sensor. 3 out of 4 sensors failed with the same problem. I’m going to try the Dexcom.
Hi Susan. Sorry to hear about any inconvenience you may have experienced. Is your phone Bluetooth working perfectly? If not, this can definitely cause the signal loss issue.
While switching to Dexcom is totally up to you, it may be a better option for you to first check your mobile bluetooth.
Moreover, if you have never claimed a Libre 3 reader before, you may qualify for a reader which is a lot more convenient and should probably sort out the problem. You can fill out a free eligibility check form here; https://cgmmonitors.com/bill-to-insurance/
Once you fill out the form, one of our reps will get back to you for further assistance. Hope it helps!
I’m not a CGM Monitors customer, but I do use Freestyle Libre 3 Plus. Last year after Apple sent out version 18.3.1 and I had auto updates turned on and failed to catch the fact that the sensors are not compatible yet with that update. So I’ve been waiting for the sensor to become compatible with my Iphone. I didn’t want to buy another phone trying to find another one with a version less than mine; so, I did get a free reader from Abbott. I have had issues with a discrepancy between the reader and a glucose monitor of as much as 100 points which made me not trust the sensor, actually scared me because I was trying to bring my HgbA1C down from 12.4 while adjusting my insulin dosage. The reader was showing very low lows and very high highs. I was all over the place so I didn’t trust the sensor. So, I started using both the sensor info and the glucose meter before each morning and evening insulin dose. I’m feeling more confident in the sensor readings throughout the day but I do not use the sensor to dose my insulin. I use the sensor since it lags for daily graphs, averages, and if I’m having symptoms and for alarms. It’s just an added tool to teach me and remind me to work hard to get healthy. Last night I applied a new sensor, waited an hour for it to start working, and went to bed. When I woke up the next morning to check my reader, the sensor had stopped working. I checked the daily graph and it showed it stopped at about 3 am and showed my glucose had dipped to near 50. I checked my glucose with a meter and it was 94 fasting. I have no idea what happened. Did my glucose dip that low while I was asleep? According to what you said above, compressions can make it not work properly. I had it in my left upper arm and I sleep on my left side. I am obese. As you advise and I agree, don’t use your sensor to make a drastic decision. Grab a glucose monitor and check first. Thank you.
Hello Celia. A 100 points difference is definitely not acceptable and should be reported to Abbott right away. Lodging a complaint would perhaps help you get a sensor as a compensation and give them more data to improve.
Moreover, we appreciate your approach and recommend every CGM user to compare results with a blood glucose meter whenever they notice that the readings are too off or not matching their condition. And yes, you got the compression thing right.