Dexcom 7 Sensor

So since yesterday I have had my sensor in (im trying it out) and I was just wondering if its normal for the sensor to be off? I mean I dont expect it to be right on the dot, but maybe plus or minus 20 points would be nice. I was driving across the state yesterday to go on a vacation and the sensor indiciated that my sugar was around 130 but i wasn’t feeling good. i pulled over, checked my BG and it was 34!!!

its not usually off that much. about 95% of the time for me its +/- 20. sometimes i will get a sensor that is just not quite right, spoke to tech support and they said if its constantly off to calibrate it wait 15 min calibrate again and wait another 15 min and calibrate again and it should correct itself and if not they are really good with replacing sensors that fail or are way off. Another thing to keep in mind is if there is pressure on the sensor it can throw it off too. And some spots just work better than others. so chances are you probably got a bad sensor, oh and tylenol can mess with reading too.

It’s not usually that far off. As a general rule, I won’t start the sensor for a few hours after inserting it. I don’t know why, but for me if I just insert and start, my initial calibration two hours later is way off. I’ll just end up spending the next few hours trying to get the sensor to read correctly.

Most Dex users find that the longer the sensor is in, the more accurate it becomes, even days past the 7 day mark where Dex tells you to replace the sensor. I don’t generally calibrate my Dex more than twice a day (every 12 hours) unless the readings are way off and my sensor will generally keep it’s accuracy that way. Other users say they need to calibrate more. So, like most things D, YMMV.

Good luck!

you should definitely replace the sensor
I’ve had it off by a lot too and the sensor was defective
especially while driving that is not a good thing to be below 60!

It should only be off by about 20 percent. Bear in mind 20 percent of 250 is 50 points, not 20 points. If BS is 100, cgms could veer anywhere from 80 to 120 and it would technically be “in range.” We have had Dex sensors that were very inaccurate as well as a lot of ??? for hours at a time. There was a period of time when Dex had a sensor problem… You can still get a bad batch sometimes. It is only guaranteed for seven days so if you Restart and get wonky readings on the 9th or 10th day, it usually means time is up and you need to change out the sensor.

I agree to what all have replied, as with all sensors, there is variability with each new sensor start. The more you use the Dex, the more you will figure out what works for you - example - when I began, I consistantly got the ??? the first 2 days of a new start. Now, I do not start a new insertion until a min of 5 hours after insertion, or in the morning if I insert at bedtime. Problem solved. Area I use - below the belly button, tends to stay more on track for me, above belly button, still within the 20%, but not as close AND it tends to change slower either with going up or down. So I have to be aware where I insert. I also find that the first two days are typically the worst. Depend on more the trends, not the actual numbers, so I tend to do more finger sticks the first two days of a new sensor than from day 3 on. Again, I have found the first day or two to calibrate more frequently than every 12 hours, it was suggested by my rep to calibrate when low and when high. I find it helps my Dex adjust if I do that. Good luck. I absolutely LOVE my Dex!