Wrong readings with freestyle libre 2

[Chris D]

You are amazingly helpful people. Thank You.
I should probably have made it "my own" post so sorry to Bails112.
Once again awoke this morning to a 2.9 reading on the Libre. Had been low for 3 hours. Instant prick test and 7.6 on that.
I had eaten a slice of wholemeal bread before going to bed to "help me make it through the night".
I am a high sugar person who would have to OD severely on an insulin injection to go low, but when the libre shows red, its a guaranteed "wake up now" situation.
Anyway, I rang Abbott Labs and after a 15 minute basic Q&A, they are sending a new sensor for free and a returns kit. Easy as pie. Mmmmm pie.
New sensor warming up.

 

[MarkD72]

I took up the free trial Libre2, the new one that gives 15 days rather than 14 as having been diagnosed T2 18 months ago thought I would give it a go more out of curiosity than anything.

But I 100% will not be self funding it as like another poster said it gives me consistently higher readings than a finger prick. I would say it is 9 times out 10 giving a reading in the 7s or 8s and when I finger prick I am low 6s. Literally just done a finger prick of 6.2 and Libre telling me 7.7.

Basically lost all faith in it tbh so wont bother again and only wanted to try and see if there were any patterns to my levels that would be useful to me to understand so could work around them.

Have my yrly A1C next month so be interesting what that comes back as last time I relied solely on finger pricks and had a result of 5.7 although was strict keto then. Not so strict now but would still expect a result in the low to middle 6's.

 

[Martin2025]

Hi
Had hypo alerts on this yesterday 2.9, checked with finger and was 4.4. Believe me if I was 2.9 I would have felt like my face had drained of colour and there would have been sweat pouring off my head

 

[Melgar]

There is an allowable error of 15% -/+ for all blood sugar measuring devices set again a lab calibrated meter. Given that measure of error, results can vary as both types of meter carry a degree of error.

I should also mention that the Libre sensor carries a reading lag due to it measuring blood in the interstitial fluid which takes the blood a little longer to get into the fluid rather than meters that measure your blood directly.
Edited to add last paragraph.

 

[Martin2025]

There is an allowable error of 15% -/+ for all blood sugar measuring devices set again a lab calibrated meter. Given that measure of error, results can vary as both types of meter carry a degree of error.

I should also mention that the Libre sensor carries a reading lag due to it measuring blood in the interstitial fluid which takes the blood a little longer to get into the fluid rather than meters that measure your blood directly.
Edited to add last paragraph.

Thankyou, that is very helpful

 

[searley]

You are amazingly helpful people. Thank You.
I should probably have made it "my own" post so sorry to Bails112.
Once again awoke this morning to a 2.9 reading on the Libre. Had been low for 3 hours. Instant prick test and 7.6 on that.
I had eaten a slice of wholemeal bread before going to bed to "help me make it through the night".
I am a high sugar person who would have to OD severely on an insulin injection to go low, but when the libre shows red, its a guaranteed "wake up now" situation.
Anyway, I rang Abbott Labs and after a 15 minute basic Q&A, they are sending a new sensor for free and a returns kit. Easy as pie. Mmmmm pie.
New sensor warming up.

Sleeping on the sensor or excessive pressure on the sensor can cause low readings

The sensor does not read blood it’s fluid under the skin so dehydration can cause inaccuracy

Failing sensors will often read low