Inaccuracies in dexcom

Noticed some big inaccuracies in my dexcom the last few days - swapped one out and now a second - just jumps all over the place
My theory is tied to my weight loss as I’ve realized as I get down to lower body fat my visceral fat has gone down and my top layer of fat on my stomach has gone all soft and squishy - very disheartening to see that
Dexcom were no help - but checking on line when you are losing fat at some point the fat deposits on your surface fat start to break down and are temporarily replaced by water until you body adjusts (and you stop losing weight for a little time) and it all tightens up
I think as there is more water swirling around in there it’s making the dexcom inaccurate
It should tighten up shortly - but a question for those out there that are skinny and have limited fat on their stomach which I am planning to achieve (washboard abs) - where do you put your dexcom ?


I’ve always said (for 2 years now)…the Dexcom is GREAT…for seeing trends. Seeing times where you may be going low, or high…but at least for Liam, his numbers are hardly ever accurate. I read and hear many people say their CGM is always accurate, but it’s been our case, that 75% of the time it says Liam is low…he’s actually not. (i.e., it will read 65 45-degrees down and, when finger checked, he’s 95 or 105.) We have many many times each day where this happens for us. So…we have gotten to the point that we don’t even stress too much over the percentages (especially the lows/severe lows), because 7 out of 10 “lows” that are registered on the CGM aren’t actually lows.

We put Liam’s CGM’s on his right and left upper arm/bicep and we swap out every 2 weeks.


My son is skinny. We often have a hard time getting a good signal. Unfortunately, the belly seems to be the best location so far.

We keep the arms and the back for pump sites, and the belly and the thighs/legs for the CGM. Upper thighs are better than lower, but are noisier than the belly and don’t last as long. We haven’t tried torso sites yet (I know @Eric is using some for a pump site).

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Agree. Mine is almost always about 1 or 2 mmol higher or lower than my fingerstick, so I never rely on it for bolusing (except maybe for that 2 a.m. correction when I really can’t be bothered to get up and test). But for trends, priceless.

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And for what it’s worth, I’ve found that CGMs do not seem to mind areas of lipohypertrophy, or bumps, which are a no-go zone for pump insertions. My Dexcoms have been reliable, comfortable, and long-lived there.


Slightly off topic, but I remember seeing another thread comparing the accuracy of the Dexcom to the Freestyle Libre (Libre was consitently higher), but if Dexcom is innacurate as well, and you’re using it just to see trends, is it a bad idea to go with the Libre? I still haven’t gotten the Dex covered, and nearing EOY I won’t be able to afford it at the beginning of next year, so I was thinking about asking my doc to prescribe the Libre as a temporary thing, to see if it might be covered instead.