Hi, all! Just setup my Dexcom G6 this afternoon. Within how many mg/dL variance is “okay” when checking the Dexcom vs finger stick/meter?
@Dev_Renae Devin, if your blood sugar isn’t rising or falling it should be pretty close. If you just ate or if you are exercising it can be substantially different.
If the error on the CGM adds to the error of a finger stick machine then I would say 20% unless your blood sugar is changing. A before meal number where you weren’t just exercising if your CGM says 180 your finger stick should say 216 to 144 or something is wrong.
1 Like
Hi Devin @Dev_Renae, it says someplace in the Dexcom literature that during the first day it is possible that readings might be a bit off.
As @Joe said, if your BGL [body glucose level] is changing the differences between CGM and BGM could be significant; I try to do my comparisons / calibrations at a point of low activity and after meals ‘bumps’ have leveled off - like just a few minutes ago at 10:30 PM. My difference just now was 4 mg/dl.
1 Like
@joe and @Dennis, thank you for your insight. Got any on signal loss? I feel like I am constantly being alerted that the signal is lost, whether I’m over 20 feet away or right on top of it. Technology 
1 Like
First Devin @Dev_Renae, have the readings between CGM and BGM become closer now that your sensor has been in for at least a day?
I occasionally get signal loss during the night when my receiver is within six feet of my sensor; I attribute this to sleeping position - it clears itself within five minutes, usually. A month ago I kept getting signal loss a couple of times a day for a few days - first I was thinking it might be a problem with the new transmitter I began using - I called Dexcom [they sent a replacement sensor] and reviewed with me my insertion technique. End story, a few days later when I began a new sensor everything was fine. No explanation for the signal loss issue; my guess is that the transmitter and sensor didn’t mate properly.
My readings have been closer! I’ll chalk it up to an adjustment period.
hi @Dev_Renae, that’s good to hear - I wanted to reply to the signal loss issue. The CGM all use Bluetooth wireless between the CGM transmitter and receiver. Bluetooth can be affected by florescent lighting, WiFi, microwave ovens, and older telephone handsets.
Write down when these happen and if it’s only happening overnight, or if it’s always in a certain room, or if it’s random. if it’s always in the same room, you can look at your WiFi antenna or other common interference and do your best to relocate and separate.
If the loss is random, then signal loss is most likely due to the transmitter, (when in doubt - replace the transmitter), so it’s a phone call to customer service that gets you a replacement transmitter - the thing on top of the CGM sensor. Then it could always be the receiver. but it’s usually the last thing to get replaced Bluetooth is very weak, so my general comment is the manufacturers “coulda done” a better job but bluetooth is cheap to integrate so that’s why all CGM work this way.
good luck!
Thank you for enlightening me to the many factors that could be interfering, @joe! I was at my parents house and they have more satellite WiFi. Since leaving their house I haven’t had many issues with losing signal.
If it flares up again or I find myself still having frequent issues, I will contact customer service.