Ideal BG range?

I’ve been wondering, what’s everyone’s goal BG range? What’s best to try to stick to for minimal complications in the long run? In pregnancy I was told to stay <95 fasting and <140 1 hr post-prandial/<120 @2 hrs, so that’s what I’ve been sticking to since then.


We don’t have specific goals like that. Our overall range is a moving target but I currently have the LOW and HIGH thresholds on Dexcom at 80 and 140. We move them up when we are getting really discouraged with having lower than 70% in range, and move them down when we’re really rocking things and Samson’s BG is hovering on the lower end.

His pump targets are 120 night, 110 daytime. We could probably lower both of those by 10 eventually but I want his standard deviation below 40 before I attempt that.


I always want to be below 100.

But I target BG movement and direction, not just a number. So I might be at 90 and rising, and I would hit it, because there is no point waiting to go over before adjusting.

And the main rule is - don’t be upset if you are not in range. Just fix it the best you can and don’t stress about it.

I don’t really have a low number that I try to stay above. That is just based on feeling. If I feel low, I eat. Otherwise I just keep an eye on it and make sure it is not a rapid drop.

That makes sense, since things are always changing, and I can only imagine how much things vary with a child!

This one is hard for me right now with finger pricks and how often I test (which is still quite a bit), because unless I get obsessive and start checking every 15-30 mins, I don’t know what direction I’m headed, though I try to do my best to catch highs before they’re actually high (or lows before they’re low). I’ve treated “lows” several times in the 70s/80s because I felt like I was dropping fast, so I’m with you on not really having a target there.

And do you really manage to stay <100 most of the time?!

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Yep, absolutely! The drop is just as important as the number. I can feel low at 70 too, if I am dropping quickly. It is silly to wait until you get to a certain number!

Some days better than others. :wink:
But it is a reasonable target for me on some days, depending on what I am doing. But I don’t ever make it an obsession. If it tops 100, or 120, or 150, no big deal. Just fix and keep going.


Wow. I had a blissful couple of weeks at the end of my pregnancy where insulin resistance was dropping, and I had perfected things so I stayed <100 that whole time. I haven’t quite gotten back to that yet, due to several factors, but I hope to at some point.


It is very difficult for most people. @Eric does a lot of running every day, and is able to do what a lot of us can’t do!

For us, 1.5 years ago we started at 90-150, then progressively moved to 70-120 for a target range, where we are today. But our target range does not mean in any way that we are able to be there all the time…

We now aim for 100 rather than 120, where we started. We also want to be in what we call “the lower part of the range”, i.e. we really try to be in the 70-100 range if possible. So, if we are at 105 or 10 we won’t correct, but at 115 or 120 we probably will, depending upon how stable we are.

When we are sick or in challenging circumstances, we do not hesitate in widening the range. Recently, my son went to sleepaway camp, in a place where they weren’t able to deal well with kids with diabetes. So I asked him to change his range to 90-150 for the night, 80-130 for the day. And, as @TiaG said, when variability is high we tend to widen the range. Some weeks are bad.

We would never be able to do that without a CGM btw.

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As a separate thought:

We at FUD are VERY aggressive at where we aim compared to most people.

We recently went to an advanced diabetes class where there was a smart teenage girl attending with her parents, I think a junior in HS. She was above 250 and hesitant to correct right away while class was going on. Even the nurse teaching the class was not feeling in a hurry to correct. This was extraordinary for us – anathema! We did not say anything, but my son asked me afterwards what was going on. He was phased.

The thing is – if more people were better educated about D, I think they would aim much higher – i.e. lower…


I think mainly in mmol/l so what is a nice round number in mmol/l is not in mg/dl.

My target is 90 (5.0). I am happy in the range of 80 to 118 (4.5 to 6.0). This is my do nothing range - no adjustments unless I see the BG moving. This is only possible with a CGM.

My normal range of operation is 70 to 144 (3.8 to 8.0). This is where my blood sugars spend most of their time - generally over 85% to 90% of the time

Over 180 (10) I will agressively correct.
Under 50 (2.8) I will agressively eat.

Everywhere else I tend to try to be rational with my decisions :laughing:


First, @Pianoplayer7008 I swear you’re sitting at home sometimes writing the posts I’m imagining in my head. Your question is just what I was wondering this weekend!!

And, this reply stuck out:

That’s really interesting. I wonder if it was because she was in class? Seems strange.

We just went to EH’s CDE nurse on Thursday, who was somewhat horrified concerned about his low BG in the last month. Mind you, he’s had a bunch of highs, but that wasn’t the concern. So it’s interesting you witnessed a similar attitude at the diabetes education class.

We like EH’s endo and CDE generally. She listens and doesn’t usually give awful advice (5th endo in 11 years). She’s supportive and willing to write a script for what he wants to try. But this time she was really concentrating on the lows. And he feels icky at 50, sure, but also awful at 250, so the focus on one end of the spectrum, not both, seemed strange. She mentioned some newer research which identified hypoglycemic episodes as more damaging to the brain than high BG issues, but we’ve yet to get that article specifically from her. EH’s emailed and I’ll post it if I get it.

I began to wonder while sitting there if FUD folks were all far more aggressive than “normal” recommendations about their range. And what a normal range should actually be. I’ve been reading the other threads and am looking forward to having time to read the longer articles linked there tomorrow.

Anyhow, timely post and good suggestions here. Food for thought certainly.


Like @TravelingOn I wonder if this was deliberate because she didn’t want to go low in class. I’ve done the same at times: let myself run a little high so I don’t crash during a meeting, an interview, a seminar, a night at the theatre – anywhere it could be inconvenient or awkward (“And why do you think you’re the best person for this job?” “Want sugar … want sugar …”).

Then again, she could have one of those doctors or CDEs who says YOU CAN’T GO LOW YOU MUSTN’T GO LOW IT’S TOO DANGEROUS OMG DON’T DON’T DON’T! Even at my big-city-hospital diabetes-research-centre clinic, my endo says I shouldn’t try to get my A1c in the 5’s because I’ll have TOO MANY HYPO EPISODES OMG DON’T DON’T DON’T. Sigh …


It gets harder… I used to be able to do that… now if I’m able to not have any spikes over 150 I consider it a great day…
1u of bolus used to cover 25 carbs too… now more like 1:4

I would consider perfect control to be staying between 70-100 before meals and few spikes over 150.

Non diabetics blood sugars spike after eating too, they just come back down relatively quickly

@Sam, wow that seems like a dramatic change… do you have any idea why it’s changed so much? Or are you just referring to the difference between how things were in honeymoon versus now?

Just honeymoon vs now I guess… very little insulin yielded near perfect control then… now a whole lot more and it still doesn’t work as well

Well, I actually don’t agree that lows are benign. For one, a bad low can kill you much quicker than a bad high, and for another, some studies suggest that repeated lows can lead to cardiac autonomic neuropathy, and impair brain function in young kids who have them. There are also studies showing a cascade of inflammatory chemicals flood the system after hypos, though pinning that cascade to long-term damage is trickier. What’s also not clear is whether, for instance, lows do cause damage at a certain rate, but that may be counteracted by the reduced glucose exposure, and so there may be some physiological tradeoff for each person where they’re having the optimal ratio of lows/highs to prevent complications. Also, while Samson seems to feel crummy with extended highs, he does not feel bad when he briefly spikes up to 200 and then zooms back down. He also feels extra crummy if he’s having an extended low. So there’s that.

So I do think an endo should be dissuading people from just running low on average and ocusing aggressively on removing those lows. I think targeting something like 80 is probably too aggressive for most people. But I think where CDEs and Endos are wrong is the idea that having a low A1C means you have to have a lot of hypos. If the only way to target an A1C of 5.8 was to be hypo 20 percent of the time – I’d say that’s not a tradeoff that’s worth it. But I think newer technology makes that a false correlation.

What we’ve found with Samson is that _having more highs means having more lows._ All of his settings, from his ISF to his DIA to his basal rate to his carbF, are predicated on a certain blood sugar range. But studies demonstrate that insulin sensitivity goes down the higher your BG goes. So once you’re in the higher range, you need higher and more uncertain insulin doses to get down. Most of his lows nowadays occur after aggressively correcting a high.

So my opinion is that if endos looked at that data, they’d figure out that the first step to eliminating a lot of lows might be figuring out how to prevent the highs.

At least that’s my opinion.

As for not correcting a 250 – I think that while that’s a bad standard practice, I can imagine scenarios where I would not do that for Samson. Like if he’s in gymnastics class and I had just given him a ton of insulin for carbs and I anticipate him dropping. We don’t know all the circumstances that occurred before.


For our son Liam we have 70 and 160 as our thresholds. During the night I set the low alarm to 100 so that I can treat early to prevent a true low.

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I agree with @TiaG on both counts:

  • lows are NOT benign.

  • more highs means more lows:

It is VERY difficult to correct a nasty hormone high without going low. I love what @TiaG is writing here:

So I also think that correcting early and hard is better. But I don’t subscribe to the theory that severe lows are OK. We correct very aggressively. But we also manually test like crazy when we get lower. It is not unusual for us to test 20 times in a really bad day – thank god not every day. We almost only hand-test for lows, much less for highs.


Lows can cause you danger in the present, like if you are driving. And you may not wake up from a low.

But long-term, the danger of a low is often overrated. At least for cognitive function in older kids and adults (please note the word “older”).

The simplest aphorism, which I have often heard - lows might kill you today, but highs will kill you tomorrow.

I’ve never regretted working under that philosophy.

No evidence of substantial long-term declines in cognitive function was found in a large group of patients with type 1 diabetes who were carefully followed for an average of 18 years, despite relatively high rates of recurrent severe hypoglycemia.


I agree with @Eric. So far, for older kids and adults, research has shown that there is no cognitive danger in lows that you survive, but there is in highs.


The problem is it’s exceedingly difficult to quantify even what “normal” blood sugar actually looks like let alone well controlled diabetic blood sugar, and so many disease mechanisms are unknown. There is more to developing or avoiding complications than simply tightly managed blood sugar. The body is a complex system and diabetes is a complex disease but we always simply conceptualize it as nothing more than blood sugar levels. We are very limited in both our comprehension and in our tools.