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If I Knew Then: Continuous Glucose Monitoring – Dexcom.

I tried my first CGM system back in 2006 (this post outlines the very first awkward sensor application) and have spent the last seven years or so being thankful that this technology exists.  If I knew then what I know now … actually, I started on a CGM as quickly as I could, and stayed on it.  Why I wanted a CGM is an easy question to answer, but there are a few things I wish I had known before starting out:

I wish I had known that some of the sensors would hurt.  So many diabetes devices are branded with “pain-free!” and “barely feel it!” advertising taglines, which I think is crap.  We’re talking about a needle that pierces your skin and leaves a wire behind, underneath your skin, for a week at a time.  To think that every sensor will glide under your skin with barely a whisper is bullshit.  Some of the sensors hurt like hell when they go through my skin, and sometimes it takes an hour, or a day, for the site to settle down and not feel so tender.  But most often, it is a reasonably quick pinch and then reasonably painless for the duration of the wear.  Your mileage may vary with each and every sensor.

I wish I had known the data would be addictive at first.  The first time I wore a Dexcom sensor, it was back in 2006 and was one of the first marketed versions of the system.  But I was hooked on the data.  I looked at the receiver every five minutes and went bonkers trying to make sense of the trends.  The trouble was that the readings were far less accurate back on the Dexcom STS, but I took them as seriously as the numbers on my glucose meter.  For the first few weeks of wearing the Dexcom, I drowned in data, obsessively checking it and chasing slight blood sugar climbs with aggressive correction boluses.  I needed to learn to let the data flow into my management, not change the flow of my management.

I wish I had known I would go through a data burnout – and that’s okay.  After I gave birth to my daughter, I went through some post-pregnancy burnout (adjusting to motherhood put my diabetes on the back burner for a few months) and for several weeks, the Dexcom was used to monitor my overnights (watching for lows), but not much else.  I wasn’t in a mental state to micro-manage my numbers, and instead I needed the Dexcom graph to confirm that I was at a stable enough blood sugar to take care of my kid.  The data was too much at times, and I frequently turned off the high alarm because it BEEP!ed relentlessly.

I wish I had known that thresholds were individual choices.  Everyone manages their diabetes in a different way, and even one, single person can have varying styles and preferences.  For a few years, I wanted to see my blood sugars between 60 – 220 mg/dL.  When I needed/wanted tighter management (pre-pregnancy and pregnancy), my thresholds were between  60 – 140 mg/dL.  And now, I keep my high alarm set at 140 mg/dL.  I like knowing when my blood sugars go over 140 mg/dL because that gives me a chance to head them off at the pass and keep them from climbing into the 180′s and 200′s.  Some people roll their eyes at wide thresholds, while others judge for not having the lines “tight enough.”  Where you set your CGM alarms is a personal decision and one that needs to work for you and your medical team.

I wish I had known, and had been ready to accept, the fact that wearing a second device was going to be a pain in the ass.  I wear my sensor on my outer thigh and the bulge is pretty obvious at times.  When I go running, you can clearly see the outline of the sensor through my running pants (and you can almost read the word “Dexcom” through running tights).  In a more fitted dress, the lump on my thigh is unmistakable.  And sometimes if the sensor is a tough too high or too low, it’s right underneath where the pocket of my jeans sits, making it feel particularly lumpy and awkward.  Of course, there are plenty of times when it’s barely noticeable, if at all.  (And it’s always fun, and a bit cheeky, to talk about “the bulge in my pants.”)

I wish I had known that I would eventually learn to trust the algorithm.  At first, I had to learn how to use my CGM, and I had to let the transmitter “learn” me.  The numbers I saw, when compared to my meter back in 2006, weren’t close, but I needed to understand that the CGM provides trends, not exact blood sugar results.  (The thing doesn’t even test blood sugar, but instead interstitial fluid.  Knowing that, however, still doesn’t make me want to throw all technologies across the room when the meter and the CGM are 100 points apart.)  And even now, using the most recent iteration of the Dexcom system (the G4 Platinum), the results are almost spot-on with my meter, but I need to remind myself to test my blood sugar to confirm how accurate the CGM is now.

I wish I had known that there could be an allergic reaction to the Dexcom sensors, but that it could be managed with someone as simple as a high-tech bandaid.  After spending months dealing with a very volatile rash caused by my skin reacting to the Dexcom sensor adhesive, a reader suggested that I use a Johnson & Johnson Toughpad underneath my sensor.  This simple solution worked to cure my Dexcom rash.

I wish I had known that the information I (hunt and) gather from my Dexcom data has made my diabetes easier to wrangle in.  Sure, the thing alarms all the time and yes, wearing a device isn’t ideal.  But when it wakes me up in the middle of the night because my blood sugar has dipped below 60 mg/dL, or when I can check it before driving and see, with confidence, that my blood sugars are stable before getting behind the wheel?  For me, that makes any and all of the inconveniences worth it.

What did you wish you had known, before trying out a CGM?

17 Comments Post a comment
  1. Michelle #

    From the perspective of a parent of a child with diabetes, I wish I had known that CGM would change the way we ‘do’ diabetes – both good and bad. (but far more good than bad). I think from my teen’s point of view, diabetes is more intrusive now, but from a parental point of view, I spend far less time asking him to check so that “I” know what’s going on, and can leave him out of the minuscule ridiculousness that is diabetes. It really allows us all to have some small ability to ignore diabetes until it’s time to pay attention. It does the worrying for us. “Is the correction working? ” “are the glucose tabs bringing you up fast enough?” It seems to give our brains a bit of a rest. That’s a good thing, in my book. He’s going to have it for a long time

    01/21/14; 10:02 am
  2. Hi Keri,

    I’m just learning to adjust to my CGM. I started just over a month ago and have some pretty big frustrations. (<a href="; target="_blank"Faulty alarms telling me my sugar is below 60, when, in fact, it's approaching 170; searing, burning pain when first inserting a sensor; and some other minor difficulties.)

    However, I like a lot of the tools that you mentioned: seeing what my overnight trends are; learning how to read the trends; being able to drive with confidence that my sugar won’t bottom out without warning.

    As I said, I only started CGM and pump use a short time ago. I’m curious why you chose the Dexcom when you did. Were there any other products available? Have you ever considered going with any other products?



    01/21/14; 10:24 am
  3. Christine #

    I wish I had known that stretch marks are considered scars and to be careful not to insert to close to them. And I wish I had a map of my abdomen so as to not puncture capillaries hiding under my skin.

    01/21/14; 11:15 am
  4. Ginger Vieira #

    I appreciate this incredibly. I was scolded and roared at by a CDE-in-training-with-diabetes for putting my high-alarm at 140 mg/dL. Like you said, it’s a personal choice depending on your goals and where you’re at in your life with diabetes.

    01/21/14; 12:29 pm
  5. Gayle #

    I wish I knew that Dexcom is not Mac compatible. In 2014.

    01/21/14; 1:34 pm
    • YES. THIS!!!!

      01/21/14; 2:04 pm
    • Haha! Yup! This :)

      Also, the biggest lesson for me was to change the “snooze” on the alarms. I have my high alert set relatively low. I want to know when I am crossing the threshold so that I can make adjustments but I don’t necessarily need to be reminded every 30 minutes that I am still there (while I am waiting for the insulin to actually work).

      01/25/14; 5:37 pm
  6. I wish I had known that it’s okay to compare different vendors. Better than okay… necessary! And that it’s still okay to have buyer’s regret after picking one over the other because no CGM is perfect.

    01/21/14; 2:21 pm
  7. Leah M #

    What Gayle said! And I wish I had known that your favorite phrase, “your diabetes may vary” means that it can vary by hour, by day, by month, by phase of the moon, etc. I love my CGM–the current Dex is sooo much better than their first gen device, which completely turned me off to CGM for a while. But I also hate my CGM because of the data overload. I have no idea how my endocrinologist makes sense of it because there’s no such thing as a pattern or a typical day. But the data doesn’t judge me, and for that I am thankful.

    01/21/14; 7:09 pm
  8. Sandy T #

    I’m just glad you posted this! I keep telling myself i need to try mine again. Love the idea of putting the sensor on the leg. Was on the stomach, and oh my goodness did it get in the way! waistband anyone???

    Overall, I wish I had known to turn off all the alarms when I first started. It alarmed every 15 minutes the first 36 hours, which was miserable (and very distracting at work).

    01/21/14; 9:30 pm
  9. Caitie #

    Thanks for posting this! So incredibly timely! I’ve had diabetes for… almost 11 weeks now and there is great debate with my family about whether it is worth getting CGM before I can get a pump. Seeing my Diabetes educators on Friday! Gives me things to think about/talk about with them! Do many people get CGM without pumping?

    01/22/14; 6:31 pm
    • Kara #

      I’ve had type 1 for about a year now and have only used pens and the contour usb as my main tools. I’m not looking to get a pump YET but currently I am trial running the older version of the Dexcom. I didn’t know until last Monday people could use a CGM without the pump. THANKS PHYSICAN CARE TEAM. I’m doing lots of research on it now.. which I have learned is where you will learn most things.. researching outside of the doctors office. Right now my main concern is how much it will cost me, if its not extreme I’m going to go ahead and get it to support my glucose monitoring. I have found its a lot harder to stop and check my sugar after I eat or when I go out to the bars. I plan to use the CGM to help me learn how my body reacts to certain foods, how far in advance I need to give my meal time insulin, etc. I don’t think I will wear it everyday of my life, because it was certainly uncomfortable last night, but we will see!

      02/15/14; 1:58 pm
  10. Jack Milford #

    Does the new Dexcom use the same sensors as the earlier version, and are they still so painful to insert? I am considering getting one when the new Animas pump, with Dexcom CGM coordination, becomes available, but am averse to self-inflicted PAIN!

    01/23/14; 8:58 am
    • They are very similar to the Seven Plus sensors, but the wire is slightly thinner and the transmitter is slightly bigger. Details are on the website, but from personal experience, I haven’t found too much difference, feeling-wise, between the Seven Plus and the G4 sensors. Accuracy-wise, though, the G4 is badass. :)

      01/23/14; 11:01 am
  11. Kerri I love this blog post. You read my mind on some of these things. I too had an extreme case of information overload at first but now I am use to it, I have adjusted.

    I wish I would have known how much “easier” it would make my life with Diabetes, sooner. I cannot go one day without my Dexcom and its data and keeping me on track. I have taken it off after a sensor ended for a day or two in the past and those two days my blood sugars were a mess. Dexcom keeps me on track for sure.

    I would have gone on a Dexcom as soon as it came out if I would have known of its existence and if my previous insurance company would have been approving them. They were only on a case by case basis in 2011, which is insane.

    Dexcom is still a totally foreign word in my area and it drives me crazy, I want to tell every single person with type 1 in my area about it and help them get on it.

    01/23/14; 11:27 am
  12. elsiroomom #

    I wish I had been prepared for the emotion of realizing what was happening “in between the finger pokes.” That the in-range number we felt so good about at finger-poke time had only arrived after his BG had come skiing down a peak like Everest 15 minutes earlier. That his breakfast peak was not just 250, but often well into the 300s sometimes.
    Of course, what we’ve been able to learn about that’s happening “in between the finger pokes” has been immeasurably useful in improving our management. For example, we’ve learned that he needs a lot more insulin from 9 pm to 1 am, and that we can change that basal without sending him low. We’ve learned that he really IS dropping over 100 points during a 20 minute recess. And we’ve got much more learning ahead, when get a new, less intrusive, more comfortable sensor this time around.

    01/28/14; 4:17 pm
  13. Dan McFee #

    In the next few years CGM’s are going to become practically mandatory now that research suggests that fluctuation is just as harmfull as the number itself.

    03/20/14; 11:51 pm

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