Dexcom Seven false highs and lows

Bear with me if this question has already been asked, as I am new to this forum =) My son just started using the Seven Plus a couple of weeks ago and we have so many issues with false highs and lows. When I calibrate it with his fingerstick reading it continually says error because the readings are obviously not matching up. I called the company and they did send out a replacement, but now my son doesn’t really want to use it anymore because it is frustrating with all the false numbers. Any suggestions so the new one doesn’t do the same thing? Thanks!

i personally use the minimed CGM but thought I might help a little not to switch you over or anything. I hear with dex com if you have tylenol in your system you can get false high readings now I am not sure that is the case for you but a thought none the less.I am sure there are many a dex com users here who could give you so advice.

I was told that, but luckily he hasn’t taken any tylenol or anything like that recently. I appreciate the help =)

Is his BG going up or down really fast at the time? I know that it’s supposed to be able to handle that, but i think it’s only to a certain limit.

How far are they off after calibrating? I hear it is normal for it to be off 15 points (there is some information at the back of the users manual about expected accuracy). Also try calibrating at different glucose levels as the more range of information you give it the better it will be over that range. How many sensors have you tried and have they all had the same problem (it can’t be too many since you say you have only had it a couple of weeks)? I hear of people having an occasional sensor problem but it is rare and I suppose it is possible for a box of sensors to be bad as they probably came from the same lot but I’m sure this is even more rare. I hear Dexcom is very good about replacing suspected bad sensors so try to get a replacement and see if the problem persists. Let us know what happens.

Keep in mind that the CGM is definitely a trend and will rarely match up with fingersticks. I use a MM CGM and although I like it a lot, I also have false highs and lows - primarily on the day of start up and the first 24 horus after until it settles in. I have kept a sensor on for 6 days so far with the MM (their recommeded/guaranteed is 3) but have much better correlations after the first couple of days. I also make sure I am calibrating when I am not rapidly changing BG levels (such as fasting or before a meal - and there is a lag time with the fingersticks to the interstitial sensor readings), and I definitly OVER calibrated it in the beginning - more than the recommended 3-4 times a day and that definitley contributed to the difference. I don’t know if there is such a recommendation with the Dex or not.