Dexcom platinum 4 and no Hypo symptoms since having the pump

Today my daughter after having no hypo symptoms after 3 weeks we have got the dexcom inserted but it’s not accurate with the finger prick test . For instance it’s saying 6.4 on the Cgm and the finger test says 3.9 . This is so disappointing because we thought this would help notify my 15 year old daughter and give us all some security . We have followed all instructions but it seems like it’s not accurate at all . Anyone had any kind of problems like this ?
Any help ??

1st 24 hours or so, the sensor is still acclimating, so Dexcom says not to worry if the results are somewhat erratic in that period. It should settle down after that.

That said, there are things that can cause problems–e.g., if your insertion point hits a capillary that can really mess things up (look for signs of bleeding under the bandage) and you can get a bad sensor though I’ve never had one. Their tech support is quite available and helpful too.

There are “good” and “not-so-good” ways to calibrate. The following is what has worked well for my daughter:

  1. After starting a new sensor (or re-starting one that’s still working at the 7-day mark), wait at least 15 minutes between the first two calibrations.

  2. Although it can be very tempting, do not calibrate more than twice daily when requested to do so.
    *Exception: I throw in one to two extra calibrations during the first 12 hours of a new sensor. Kind of like yelling, “Are you finally understanding what I’m telling you?”
    **Sometimes I get a little calibration-happy when my daughter’s sensor is getting a little “ripe”, i.e. over 15 plus days old, if the Dex readings seem significantly wonky. At which point, she’d be better off if I just bit the bullet and put in a new sensor.

  3. ONLY CALIBRATE WHEN THE DIRECTIONAL ARROW IS HORIZONTAL. I repeat: ONLY CALIBRATE WHEN THE DIRECTIONAL ARROW IS HORIZONTAL. Trust me on this! Your sensor continues to function after the big red blood drop screams at you to calibrate right now, dammit. Tell it to hold its horses and you’ll calibrate when you’re good and ready to (when the directional arrow mellows out and becomes horizontal.) No one’s Dexcom has stopped working or imploded, creating a black hole that engulfed the universe, because they didn’t calibrate the instant the red drop of Dexcom appeared.

  4. Learn to question the accuracy of your BG meter as much as, if not more than, your Dexcom. Personally, I trust the Dexcom more often than I trust the BG meter. But my daughter’s Type 1 vibes seem to resonate exceptionally well with those of her Dexcom. I often think that my daughter and her Dexcom are as one.

Good luck. In short order, you will wonder how you lived without this miracle of diabetes technology.

5. Stay well hydrated. I believe it helps produce enough interstitial fluid that more accurately reflects BG levels.


What a handy checklist–thanks @rgcainmd! This one in particular I hadn’t encountered before:

The manual says “back to back” fingersticks and I registered that as “do it as fast as possible!!” Next time I’ll give this a try.

I haven’t done this either but I’ll give it a try. Otherwise my calibration habits are consistent with your advice. I love my Dex!

Lots of good advice so far. One other thing to remember is the lag time, interstitial fluid is 10-20 minutes behind blood glucose levels. Even when I have no arrow or a sideways arrow I’ll sometimes see a difference in the numbers but if I wait 15 minutes the Dexcom will catch up.

We only see a lag, which has been reduced to about 5 minutes with the 505 algorithm, after a low.

Interesting, I see after a high more than a low.

Now that I think about it, you’re absolutely correct. I think this slipped my mind because I EXPECT an extended lag after treating a significant high (like about 1 to 1.5 hours), whereas waiting for a low to respond to treatment is much quicker (but almost always more uncomfortable and anxiety-provoking…).

I just got mine and I followed their directions for calibrating and mine is right on the money, has been all week. Maybe your meter is off? Have you used control solution to test your meter? I wonder if you call Dexcom maybe they’ll send you new sensors in case they aren’t accurate.