Your Blood Sugar Reading is False! Here is Why.

Continuous glucose monitors, like FreeStyle Libre, Dexcom, and many others don't always provide an accurate blood sugar readings. The most common reasons why your CGM reading is off are discussed in this video.

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Disclaimer: I am not a medical professional and my videos are not medical advice. What works for me might not work for others. Please consult your medical professional regarding your diabetes treatment.

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#typeonetalks

[viniiit]

This guy should be awarded a noble prize for clarifying so many things regarding cgm.

[nancyrendel]

Thank you again for sharing your experiments. I am pre diabetic and have experienced exactly what you have personally experienced/ experimented with. Thank you also for experimenting with LFWFPB. My mother and mother in law are both typeII and I have always asked them to be sure and finger stick before taking insulin or drinking OJ when CGM shows too high or too low. I helped my mother in law lose 100 pounds and she was successfully off of fast acting insulin! She can't walk too far so I told her to just move her arms up to the side like sitting jumping jax and it brings her glucose down, as well as when she drinks more water. Thank you for posting this very important video.

[KrauseHayden]

I got IV vitamin C in a megadose (like 15 grams) and my blood sugar readings on my libre were crazy high!!! Nobody thought to tell me, and I was so confused!!! Apparently vit C is structured very similarly to glucose so the CGMs read it as such.

[TimothyGott]

I will rate this video as one of the top five most helpful videos that i have watched from you. Thank you so much for this one.

[virenp]

Here are the 10 mistakes that can cause inaccurate CGM readings, according to this video:

10. Insertion trauma: Applying a new sensor right before the old one expires can help to avoid inaccurate readings during the first 12-24 hours.
9. Not understanding that CGM measures interstitial fluid, not blood sugar: CGM readings are always a little bit delayed compared to blood glucose readings.
8. Sleeping on the sensor: This can put pressure on the sensor and cause false low readings.
7. Using the wrong brand of CGM: Different brands of CGM may work better for different people.
6. Taking too much vitamin C: Vitamin C can falsely raise CGM readings.
5. Inserting the sensor into the muscle: The sensor should be inserted into the fatty part of the back of the upper arm.
4. Comparing CGM readings to glucometer readings too often: This can lead to anxiety and frustration.
3. Using CGM in extreme temperatures: Hot temperatures can lead to false high readings, while cold temperatures can lead to false low readings.
2. Not being hydrated enough: Dehydration can lead to false high readings.
1. Not understanding that no CGM is 100% accurate: All CGMs have a margin of error.

[KrauseHayden]

This is so helpful!!! I wish someone had told me all these things like 10 years ago when I got a freestyle libre for the first time
!!

[AlvaroLojano]

You are awesome man, I finally figured out why I was having low reading during night when my glucose was good. Thank you

[Cyborkirk]

Another tip is stated in the paperwork and people don't realize it: Don't calibrate the CGM if your glucose is falling or raising, and only if it's a greater deviation of 20 mg/dL compared to a finger check.
Thanks for some of these tips I didn't know. My life has been better with a CGM (Dexcom G6), hardly ever check my glucose with a meter anymore. Makes me feel more human when complimented with an insulin pump.

[jenskaufmann]

Very interesting! Regarding the Vitamin C: I do not have any problems with the Dexcom G6. If you do run into issues I would strongly suggest rather to switch the CGM system instead of stopping to take the vitamin as is so essential for so many processes in our body.

[DecieBoi]

This is a great video, thankyou so much :)

I have so much anxiety regarding my CGM and glucose readings

[donkrapf]

If you catch the CGM on a door frame, it's possible for it to pull enough to dislodge the filament without quite pulling loose the adhesive. This will leave it looking good but you may get disastrously low readings.

[MrRainbowrooster]

A few months ago, I switched from the FS2 to the DG7. I was able to prove what I feared by wearing both devices for about 10 days. The FS2 was alway 35-75 points off. Because of that, I was having serious vision issues to the point the eye doctor had me take a brain scan (it was clear). The G7 for me is incredible and I love it. Also, on point 2 of your video, I recently discovered how true and correct you are about hydration and the effect it has on accuracy. You are right on that one as well. Thank You for all the time you make doing these videos. I will be subscribing to Patreon very son. Thank you Tom.

[AlternateF]

Excellent video as usual! Very informative. I'm using a Freestyle Libre 2 and every time I start a new sensor I get the warning about Vitamin C, but I hadn't seen any details about what impact taking too much Vitamin C would have on the CGM. Thanks for doing so much research and sharing it with us!

[lonndawg]

Well, there was a lot of very specific and real-world information in this video, you covered a lot of perceptions people have about the accuracy and the numbers they see on their meters both the CGM and the glucose monitoring systems we all have. You provided some great real-world reasoning and research into why there are real reasons why these CGM sensors read differently. And it is probably a surprising revelation to the average person that the CGM sensor is not actually reading your blood sugar level from your blood, it has a different method. After 35 years of being an insulin-dependent diabetic, the disease seems to have progressed to a point where I do need a CGM, but, the ongoing expense puts this device out of reach at this time. but seeing this video and others that you have created, is very important to me in information in order to make decisions and have a greater understanding of these devices and some interesting things that you have expressed about having diabetes in your past video history. I approach my diabetes and administering insulin in a very analytical way, which I believe you are also doing when you create your videos and express your findings on subjects like the CGM and other things concerning diabetes and its management. This video really gave fantastic information about these devices.

[gas]

Another awesome video, thanks for your effort! I have tried the Libre 1 cgm and i have experienced most of the things that you said. The most important thing, for me, is that we have to focus on the glucose trend (the direction and speed that our glucose is changing).

[ultramet]

This is a great video. Thanks. One more tip, if you take Tylenol (acetaminophen) or paracetamol that drug can interfere with the sensor reading. The readings can be falsely high.

[jbjacobs]

At least you enjoyed a glass of OJ. I miss Orange Juice so much! And bananas! Is my CGM lying to me? Yes, yes sir, it is. LOL I have fallen in love with your wry, subtle sense of humor and facial expressions (and the hilarity of the gangsta persona you had in your "7 sites for Dexcom G6"). I wasn't expecting to laugh out loud at a glucose/dexcom video. Thank you for bringing lighthearted personality to a sometimes frustrating and serious life situation that we go through with Diabetes. It can be angering that for a product that only works for 10 days and is sometimes a bit traumatic and costs an arm or leg, that it creates crazy discrepancies. I wish I had a glucose assistant, particularly to insert and remove my meter. LOL

[mystatinfreelife]

I had trouble with the Freestyle Libre 3 while I was on a backpacking trip. TWO of the sensors fell off within an hour of application. It appears (obvious in hindsight) that applying a new sensor when I got up, then starting my day's hike, was not a good idea. After discussing it with the doctor's office, we determined that I needed to put the sensor on at night before going to sleeping bag (like going to bed, except out on the trail) to allow the adhesive time to bond well before I started sweating. After that, I had no problem. (And Abbott Labs did replace the two sensors.)

Of your tips, the one about compression seems to be the one I may have been guilty of. Since m doctor only has me using 1 sensor per quarter year, I can always put it on the back of the arm that I'm less likely to sleep on, since I do often sleep on my side. Great tips! Thanks.

[johnschlesinger]

Thanks for pointing out all the possible problems with CGMs. I have considered getting one from time to time, but after watching this I'll stick to my glucometer!

[lozetchells]

Putting your CGM on 24 hours before it's needed also works for me. The downside is that, with the libre 2 at least, i find that i sometimes get premature failures on day 13. Seems that 14 day battery life really is a hard limit.