Does anyone else have the problem of the ??? marks on their dexcom. It has happened to me several times (happening now, for past 2 hours. It is right next to me and the sensor is definitely still in, so don’t get it…

It means that the sensor isn’t getting good enough info to send over. This often happens if you are laying on the sensor, or sometimes if you are dehydrates, though sometimes it just happens for no apparent reason. It’s generally best just to wait, or if it’s a sensor over 7 days old, it might just be time to change it out.

I had that happen to me a couple times when I changed the numbers - Dex thought I was 60 (for example) and my meter said I was 120. So I corrected and then corrected again. A few minutes later, I got the ???. Don’t know if that’s your problem though.

I always just stop the sensor and then restart it. You have to go through the 2 hour warmup period, but I don’t like wasting sensors that still have life in them.

Ya I had that problem yesterday and last night- I may have been dehydrated though as well as lying on the sensor so I’ll have to watch for that. It’s working fine again now.

Some sensors need a longer start time (I do) otherwise I get the ??? at startup every time. I just insert night before and start in the morning. Rapid changes in your sugars either direction can cause the ???. Insertion to close to the muscle or in the muscle I am told can cause the ???, so far I have not experienced that yet. Age of sensor, receiver to far or seperated by your body (like in a back pocket with sensor in your belly), dehydration, and complete failure of the transmitter (happened to me within the first 6 months of a new Dex.) Tech says wait 3 hours, and most of the time it corrects itself. If not, call tech support to let them know (if you are on the first week of a new sensor!).

usually means it ready for a change.

Had happened to me few times. Just ignore it for some 2 hrs or less. It will come right back. There is nothing in my knowledge that you can do to help the dex during that waiting period.

So helpful, thanks! It came back on about an hour after I wrote this post (so wasn’t working for almost 3 hours). I think it was dehydration- that makes a lot of sense.

it is only 3 days old, but think was just dehydration. thx!

Yeah, I think it was the same for me (dehydration). I get it when I am exercising sometimes- which makes sense, because I always get so thirsty when I exercise. For some reason, I don’t sweat (not sure if this is a diabetic thing).
thanks! happy it is working again for both of us!

Thanks Andy! yeah, I think you are right- had no idea about the dehydration thing, but that makes sense. Happily, it is working again.