Is it possible to Re-Develop your physical sense of lows? highs? after depending on CGM



In my ideal world, I would not be dependent on Dexcom for warning me about lows. I’m 13 years into my T1D journey. I’ve used Dexcom for probably the last six or seven years. Before Dexcom, I went off of fingersticks and how I “felt”. And a lot of times I could feel a drop, or feel a low, and then I would confirm it with a fingerstick before taking action (unless it seemed urgent enough for immediate action without testing).

I don’t know if I’m remembering it inaccurately, but I really think that I felt all of those things for most lows pre-CGM. However, I do remember being caught by surprise enough times when I was already down in the 50’s or 40’s or 30’s before I felt it. But my low symptoms were strong enough that they would wake me up from a deep sleep…which was necessary bc Lantus always dropped me in the middle of the night. It’s amazing I have any teeth left after juice boxes every night.

Adding Dexcom certainly gives me early warning of a troubling trend to correct…and it certainly caught lows for me before I did in the early days of using it. But now, I swear I don’t feel lows or drops. I might feel nauseous, or hungry, or mentally slow with lows or drops now, but it all seems so much more subtle. I don’t break out into sweats or shakes or anything textbook like I used to the early years. I got the glycemic index wrong on dinner last night and went low after finishing my extended bolus. I don’t know if the “oh shoot” feeling of seeing the CGM graph is just overriding what I would feel subtly without the Dexcom? But it’s a toss up as to whether I felt the “oh shoot I’m loaded up with insulin, finished eating a while ago, and am 57 right now trending down” jitters vs actual low jitters.

So…are my instincts just rusty? I’ve gotten so dependent on tech that I don’t know my own body anymore? Or is it a combination of tech early warning plus long duration of this disease that has changed my physiology? Do you think there is a way to redevelop my innate physical sense? [I don’t really remember feeling highs pre-CGM…or post-CGM, if that makes a difference.]


I think this is highly individual, so I can tell you how my identification of lows has progressed, but yours may be very different.

For a few years after diagnosis, my lows were very pronounced. I would shake and get all sweaty. The lows were very noticeable. Personally, I don’t think it’s possible for me to ever get back to that point.

Slowly, my identification of lows has changed, and the symptoms are heavily dependent on the slope of my cgm line/how quickly I’m dropping and how low I am.

Sometimes I don’t have symptoms for mild lows with a nearly flat slope. Eventually I’ll start to feel a little agitated and anxious, and I start to feel hungry. I can also get a bit fixated on whatever I’m doing, despite the knowledge that I have a low that needs to be treated.

If I have a steep slope, then I don’t have the fixation I just described, but I’ll feel the other symptoms much stronger (anxious/edgy and hungry).

The first symptoms of a severe low are that my joints sort of jerk. I might not be able to grasp something I’m holding because I’ll have some sort of jerking motion, or I might not be able to walk steadily because my knees will jerk weirdly. The next symptom is my vision getting spots and my tongue going numb. My memory of these events is not very good either.

The severe lows don’t happen very often, but none of my lows are accompanied by the shaking and sweating that I had in my early years after diagnosis. Now, I’ve almost always already treated the low by the time I get to the symptoms of a severe low. It just takes time for my body to catch up.

Before cgm, I only woke up to lows if I was in the 40s or low 50s and hadn’t been drinking. I do not wake up to lows in the 60s. I rely heavily on a cgm at night, and I expect that I always will.

I can identify highs much easier than I could after diagnosis, but I was a kid then so maybe that’s why. With the first sign of irritability, difficulty focusing, or remembering things, I’m guessing that my cgm is trending upward, and I need to dose.

I can usually feel a low or high during the day though. Before looking at my cgm, I think about where I feel like my bg is. I think that can help you identify the symptoms you’re feeling before you even know if you’re low or high. If your phone vibrates to send you an alarm, you could guess at the value (low/high) before you check? Maybe that would help?


Thank you, @Katers87. I always appreciate your input and perspective. It’s always very insightful. I will try feeling it before looking at it.


Thanks :hugs: You’re sweet. I love reading your posts too.


How many phone numbers do you have memorized now versus how many numbers you had memorized before cell phones came out?

Think your map reading skills have gotten better since you started having a GPS in your car?

In 2007 there was a study that compared 3,000 people and found that the younger respondents were less likely to remember some simple personal information such as family member’s birthdays or phone numbers.

Studies have shown that calculators may have decreased people’s ability with simple math problems.

A 2012 study found that 89% of those surveyed reported feeling phantom vibrations - the physical sensation that their phone was vibrating - even when it wasn’t. Researchers believe that our brains now can misinterpret physical sensations like an itch for a vibrating phone.

Of course CGM can get in the way of paying attention to the physical signals and processing all the mental signals. And thinking about all the things that you have done recently, like eating or correcting or dosing.

What you should do before you look at your CGM, is make a guess. Before every blood check, make a guess. Process all the signals, analyze what has been happening, what you have eaten, how much insulin you have in your system. Do that to keep your brain sharp. Try to know your BG before you check it and before you look at your CGM. Keep those skills sharp.

I have suggested this to @ClaudnDaye a while back:

And also suggest it to @daisymae a while back:


That’s hilarious, bc last night when I called my brother I thought to myself, “If I lost my phone, all I would know for his phone number is his area code. I seriously don’t remember his phone number starting with those three numbers…” and I never even looked at the last four digits.

So…I’ll look at the Dexcom a lot less…or at least I’ll try to guess before I look…but I wonder about balancing the utility of CGM while trying to remain independent. I mean, I depended on fingersticks before CGM. I could feel phantom lows when I really wasn’t low even pre-CGM. I still needed verification to not create a new problem for myself. And I depend mightily on my CGM for timing my preboluses…bc some days it takes 20 minutes to get going…some days it takes 70 minutes to get going…

So as I’m working on reconnecting with what I can feel…I guess I’ll be grateful that I have CGM while I have it? Bc it does concern me that down the road I may encounter a situation where the current CGM’s available don’t work well with my body. And I think it is pretty well accepted that having CGM can wildly improve self-care. Pre-CGM, my endo’s all told me that I tested too much. But timing a bolus can be the difference between spiking 150 points (or more, easily) or staying down to a 50 point spike or tanking before I eat for me. When I see that sort of difference in results due to detailed execution…it makes me want to figure a better Plan B for myself if stuff goes haywire.

Very interesting article. I always appreciate your help on everything, @Eric.


Dexcom start-up calibrations:

Guess: 140
Fingerstick: 155

I’m thinking this was completely lucky.


Allison, what I’m seeing in your discussion is something along the lines of “How will I cope if CGM stops working for me? I’d better start preparing a plan B just to be safe.”

I say don’t even think about that. Not at all. Completely dismiss it from your mind. The CGM is an incredibly useful tool, and there’s nothing wrong with becoming dependent on it to stay safe: that’s exactly what is for. It’s the same as driving a car without practicing a plan B in case the brakes suddenly stop working, or practicing how to get around the house blindfolded in case your eyes suddenly stop working.

Now I understand the attraction of being able to “use the force,” and there’s nothing wrong with guessing your BG before glancing at the CGM, but to me the development of that skill has reached obsolescence because of technology. To me it’s in the same category as telling the time by looking at the sun, or predicting the weather by looking at the sky. At one time these were vitally important skills, as without them you could be stranded out on a hunting trip after nightfall, or you could lose a hay crop because you didn’t sprint to get it under cover before the storm arrived. Now we can just look at a clock or call up a weather forecast. Sure, the phone could fail and the radio and TV stations could all go down, but I don’t think we need a lot of plan B’s for these contingencies.

Sure, practice guessing your BG if you want, but you don’t need to. You have a better tool in the CGM.

Oh, back to your original question. I haven’t heard of people getting back the full shakes and sweats that we experienced with our first few hypos, but they do say that if you can go 2 to 4 weeks with absolutely no BG ever below 70, that will re-awaken some of the lost sensations when you go hypo, because your body won’t be acclimated to low BG as a normal routine condition.


Nailed it.

When I came to FUD last year, I was at that point, though. Adhesive reactions. Trying alternate areas of my body for Dexcom. Only place it will read for me is my back. So I was in the dark on CGM for about a month while trying all these things that do work for other people, but don’t work for me. My arms won’t read CGM anymore but they used to. Thighs were a complete waste. Abdomen hated the adhesive hardcore.

So…I need to get to where I’m not suspecting the Boogeyman everywhere anymore…but I also need to cultivate some game plan of how to have a sound belief that the Boogeyman isn’t actually there. And it goes both ways. I need to be okay functioning without CGM to some extent…but I also need to be okay seeing some screwy CGM data so that I can evaluate whether that trend makes sense or it’s a red herring. CGM data has lead me to overtreating lows and generally freaking out more in the last two years. That ain’t good. Need to balance that out. I think I’ve got to meet it in the middle to where I get back on my routines that work for me and give me confidence to view CGM with some healthy skepticism.

I always like to keep my feet on the ground with anything I do. I was the same way back in my technical days…automation is great! GPS makes navigation easy! Until I was totally not paying attention to where I was over the Midwest one day and lost reliable GPS signal. Oops. Probably should have been paying attention to the interstates and other landmarks prior to getting to a point of problem solving out of necessity.

This is either not true for me…or I’m so full of sensory static from relying on CGM that my own sensations can’t beat their way to my attention. I will keep an eye on this. I do feel low symptoms after I already know I’m low…so in that way, I feel like a BG poser…like, oh yeah, I’m low, I totally knew that and NOW I feel it.


Keep in mind BG tests can be off. I can test with same drop of blood, on same or different brand meter, and be 15-20% difference, other times much closer.


That saved my life in 1993, when I pushed the brake pedal and it went all the way to the floor without slowing the car. The master cylinder was blown.

I downshifted harshly and used the handbrake without locking it and was able to stop the car before it crossed into a very busy intersection. Cars were barreling through it at over 50 mph.

I just did it without even thinking. Because I always had that ready as the plan, and we always knew what we were supposed to do in the event of a brake failure.

“Just don’t worry about it” is not a good strategy.

Just a few weeks ago I was without CGM for 9 days, because of a double transmitter failure and Dexcom getting way behind with their shipping because of the holidays (and maybe because people were stocking up at the end of the year before their deductibles reset). Several calls to Dexcom throughout the week and I was just told over and over that they were working on it. I was without CGM from December 30th to January 8th. (BTW, i was @daisymae who got me the replacement sensor before Dexcom! Bless her heart!)


And I wonder about that, too. Last night’s 57…would it have read 77 on a Contour? Is that why I didn’t feel anything?



Maybe coming from a profession where 95% of my training was for emergencies and only 5% was for normal ops feeds this mindset in myself, as well.


Lovely points made all over this thread, and I will also add that in my experience, it’s possible for the physical sensations that accompany a low to change, so you may be feeling something but possibly not equating it to a low in your mind? For years my most frequent low symptom was shaky hands, then sometime in the past few years it has changed to a slightly numb/tingly upper lip. I almost never get shaky hands now, but there is a handful of other symptoms that have started up.


I think you’re onto something!


This is one I feel too.
Sometimes accompanied with dull fuzzy head feeling.


That is a good balance, and sensible. I’m just trying to lean away from worrying about the what-if’s, because that’s demoralizing and exhausting.

That makes sense, but I think that falling out of the sky (or even just getting lost without knowing where to land) is qualitatively different from having CGM technology stop working. An air emergency doesn’t give you a lot of time to forgive mistakes while trying to mitigate the problem, so you need procedures and preparation to give you a way out. With low BG if you just take glucose if you’re in doubt, then with overwhelming probability you’ll be safe from an emergency. Planning for the possible eventuality that CGM no longer works doesn’t have the same kind of urgency. Maybe the whole question will go away if we all end up with implanted sensors or a cure.

But did you feel like you would have been in danger if you hadn’t previously figured out a plan B? When I had to do without CGM for a week because of problems with renewing the insurance pre-authorization, it was more of an “Oh, bother. Back to fingersticks and I’d better be more careful about getting a good stable BG before going to sleep.”

It looks like I was able to sneak a careful statement past you. I was being subtle because I didn’t want to pull focus from my point. Stated nakedly, I think preparation should be commensurate with the need. To go beyond that and pre-worry about problems that don’t need to be pre-solved detracts from a happy existence. The old way to say that philosophy is “We’ll cross that bridge when we come to it.”


For what it’s worth, I’ve been trying to do this since I first read it here about a year ago. But most of the time, I’m dead wrong. Between about 60 and 200, it all feels the same to me. So I have no problem relying on the technology, because I’m not likely to sense where I am physically. (Example: Today I was 90 before breakfast, I had a low-carb, low-protein breakfast, I did not eat any lunch, and I’ve been sitting at my desk for seven hours. I just thought hard about how I feel and what’s been going on and I guessed I was around 70. In fact I’m 130.)

Over nearly 50 years of diabetes, symptoms of being in the low-but-not-seriously-low range vanished. I didn’t feel low until I was suddenly sweating, shaking, and half-brain-dead. Post-CGM, and probably because I now avoid those serious lows, subtle symptoms did return after maybe half a year, but the range is limited, and they’re easily missed if I’m physically active, and so for the most part I am dependent on Dexcom (or more frequent fingersticks) and I don’t have any issue with that.


But it is not just the physical feelings. It is applying all the things you know as well.

You know what your last BG was, how long ago, how much insulin or food you have had since the last BG. You know from the last two BG’s if it was moving up or down. You know what day you are on your infusion site, if it is a good site, if you have been active recently, if your basal has been too much or too little the past few days.

It is not just how you feel, but connecting all the dots.


That’s an excellent point. I also find that when I’m doing physical labor, I don’t notice indications of hypoglycemia until I’m in the low 50s or the 40s.

Some of us don’t have the midichlorians to pull that off as well as you do. And some of us don’t have that level of dedication. But my Dex is an absolute machine, I tell you. Always watching to keep me safe. And that’s an ok way to deal with it too.