Discrepancy continuous glucose monitor vs blood testing

I am trialling a continuous glucose monitor (CGM) because with commuting and a very hectic work schedule, testing my blood glucose rigidly 1 hr after each meal is challenging practically. However, my CGM readings seem a lot lower than my blood glucose levels when I finger prick (trying to do both for a period to check accuracy). And my CGM is telling me I'm going less than 4 mmol multiple times a day. Has anyone else experienced this? I'm not sure which one to believe or why the CGM results would be so different

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What CGM are you using? This happened to me with one of the sensors, I’m using Stelo. Usually it’s pretty close with BGM.

@Aneta The FreeStyle Libre Pro CGM which was recommended by my hospital. I'll need to try another - I'll check out Stelo thanks!

I have the freestyle and I love it! I had one instance where a monitor was reading me to be below 4.0 for hours. I realized it was a defective monitor and the company sent me a new one. I’m on my 5th monitor?

Yes. This happens to me. It’s common as one reads from a blood sample and the other from your cells. A discrepancy of up to 15% is considered normal.

@Natty yes mine is showing as less than 4 basically all night and multiple times during the day. I think it must be defective. Thank you for sharing your experience!

@Aimée yes 15% difference sounds reasonable. Currently mine is 1-2 mmol different which is too large. Have asked the company to send another monitor. Thanks for sharing your insight!

Ah yeah that’s a big gap. It happened like that with my first monitor actually and they sent a replacement. Right at the start and at the end of their use they go a bit funny too.

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