Has anyone else ever seen a 100+ jump in a matter of 5 to 10 minutes?

For the past couple weeks, we’ve noticed our son jumping from some number, say 100, all the way to 200 (or higher) in just 1 or 2 ticks (5 to 10 minutes). Also, the same thing has been happening, moving downward…say 200, then only 5 or 10 minutes later, he’s 100 (or lower!)…it’s been insane lately. It’s so hard to treat effectively when the numbers have been jumping so severely.

This hasn’t happened to us, that we’ve noticed at all except until recently…

yes! We often see this with pancakes or, say, if we have treated a low that is hovering, hovering, hovering until it starts rising.
I suspect it’s actually not a true drop or rise in blood sugar, but rather that the sensor is having trouble catching up for some reason. There IS a fast rise–but from what I’ve read it’s really rather unlikely for blood sugar to rise that fast. That would be like 1200 points in an hour!


One of the many limitations of cgm… do finger tests show the same thing? Whenever the cgm doesn’t seem to make sense I always double check and often it’s way way off

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I have seen something I call a microspike, that I caught once on both the CGM and the meter, and another time just on a meter: https://forum.fudiabetes.org/t/interesting-microspike-caught-on-glucose-meter/211

I think the phenomenon is totally real. The CGM can’t follow that speed, so you see it greatly attenuated on the CGM.

I was interested in seeing what @TiaG wrote:

because, until she wrote that, I was assuming that this speed of rise and fall could all be hormones, not food (I have never seen food make my son’s BG rise that fast – but I can imagine how a toddler might react much faster).

On the other hand, when my son gets a hormone peak (which is pretty much every day), by the time his CGM is at 120 from wherever it started, say, 10 or 15 minutes (in other words when I get the high alarm), his real BG is often around 200. So I know that hormones can be that fast.

Over 50% of the time, there IS a huge jump of 100 or more believe it or not…not always, sometimes the CGM is off, but a lot of the time it isn’t. I always do 2 finger sticks also just to be sure. The craziest part is that whenever this happens, the BG’s seem to ALWAYS slow down just as quickly and suddenly just stop (arrow on the CGM disappears) and the BG’s seem to level off where they stay for a few ticks, then start heading down.

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I have noticed that some of my biggest and fastest jumps are not a result of food, but from exercise at high intensity. It is the big glycogen dump and hormones just throwing everything out all at once. And I have noticed this with BG tests (the CGM doesn’t have a clue for 30 minutes). So that made me think of possibilities for you…

Is it possible that when you are seeing this, there is something else at work besides food? Or maybe something in conjunction with food?

For example, at mealtime if he has a bunch of big brothers huddled near him, is it possible there is that normal younger brother type of instinct that he will need to scrap for what he wants? Or is there a time limit with a meal that would raise that same type of urgency and cause hormones to play a role?

I just bring this up because there are so many things that can be a part of it that we often don’t even think about! And the mindset of a little guy can be so different than our own. They worry about stuff that we wouldn’t even think twice about. It’s hard to believe, but any little thing like that can be a factor.

Anyway, not necessarily what you are seeing, but something to consider if you ever see craziness!


He does chase his brothers around a lot…maybe that’s what’s doing this. I’ll keep my eyes open for this association in the future. Thx for the idea!


Weird. I’ve always assumed it was a CGM issue because we often have those huge spikes and huge drops on the same days and they usually happen before we change out a sensor or get ??? for the first time.
But if your’e saying it’s confirmed on a finger prick, it must be physiological.
It’s almost like the system for spurting out sugar into the blood got backed up and then dumped a bunch all at once to catch up, then resumed at its normal rate or something.

Unfortunately, I see this more than I want to—less in the 5-10 minute window, but occasionally in the 20 minute window. Had several of these this week and simply could not figure it out or get off the roller coaster. Minor juice corrections (as in 2-3 sips—about an ounce) did this to me. Seems to have evened out for a bit now. I can see that in such a tiny body, things could go haywire even more quickly.

It was a totally new thing for me too. I recorded it on my calendar and am trying not to live in fear of its repetition.


@Irish, we have noticed a sequence when my boy will take, say, 3 oz of milk, and keep the same, then another 3 oz 40 min later and keep the same BG, then take another 3 oz 40 min later and go up 80 mg/dl (when his carb sensitivity is about 4.5x, so he should go up about 20 mg/dl).

We have seen this so often that I am almost ready to think that there are moments when people are hypersensitive to carbs.

It’s interesting that you say this. It’s almost as you describe it, a carb-stacking (reverse of insulin-stacking) phenomenon. That was part of my problem last week, I think too. Where waiting the normal interval simply wasn’t working and then all of a sudden the typical corrections added up to an awful roller coaster.

There were other times, however, where a simple carb correction would send me double up and a simple insulin correction would send me double down. It was a nauseating ride.

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Is it possible that you were sick or stressed? Or – pregnant?

I wondered about sickness since it was so entirely different than anything I’ve experienced over the last 12-14 months, but nothing materialized.

As to pregnancy, my surgeon would have some tough questions from me if I were.

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I’ve seen that before. Sometimes you just have to wait for the carbs to hit you. Be patient, trust that it will work. I’ve had instances where I keep taking food/carb/sugar stuff because I am low, and I know it will hit me like a tidal wave - and yes…it hits me like a tidal wave. Being patient is key.

lately i’ve been doing something that others may think is nuts, but when I have to do multiple low treatments in a row, I KNOW it will cause a huge rise. So I track the carbs, and as soon as he crosses 100 arrows up I bolus him for all the carbs minus 4, or 8, or 12, or however much I calculated upfront should be required to absorb the excess IOB.

Sometimes it requires a further snack but mostly it just prevents the high from going too too high.


Can you give an example of your calculation?

I do that sometimes too, when I am predicting a glucose flood to happen later. That is not nuts at all.

Okay, so let’s say he’s dropping low with insulin on board (IOB) of 0.4 units.

Let’s say carbF is 1:20. So 4 grams of carbs should require 4 grams/20 grams carb/unit insulin = 0.2 units of insulin to process. To absorb that initial IOB would require twice that amount, or 8 grams of carbs.

Let’s say that even after treating preemptively, he’s just hovering in the low-to-mid-60s for an hour, and so I have to give him multiple repeat treatments. Over the course of an hour I give him 16 grams of carbs total.

But 8 grams of carbs were “covered” by the existing IOB that was there when he started to go low. So I bolus for the remaining 8 grams of carbs (bolus = .4 units) once he’s rising steeply and above 100. Sometimes I give a little less (0.3 or 0.2 units) if he doesn’t seem to be rising super fast, and sometimes I give that full amount (0.4 units).

As a sanity check, I would expect that if his ISF=200 I would predict that the extra amount of insulin I gave would shave 50 points off his final blood sugar: 0.4 units * 200 poins/unit = 50 points.

Does that make sense?


I think the other thing to realize here is that because we are using a proxy artificial pancreas, when he’s going low it will zero temp basal him for as long as he’s low or dropping. That means that while he’s hovering in the 60s he’s also developing quite a negative IOB balance and has a growing insulin deficit until he starts rising. So in a way I also see it as just giving him back his missed basal that he would have been getting had he not been low.

Make sense?


Yes, it does. I understand your math, and I understand the reasoning on basal deficit.

I am still thinking through the thought of the advance bolus and the reason whey the carbs flood later than they should be expected. You don’t argue with success so, if this works for you, there must be an explanation for the late flood – which I have seen happen many times. But I haven’t quite figured that part out.

The interesting thing I am understanding here is – we all (or many) see a mysterious phenomenon involving high sensitivity to carbs for some reason after a persistent low. This is not just one of us.

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