When I was diagnosed in the USA, I learned all about blood sugar in mg/dl. I was taught that a low blood sugar was anything under 70 mg/dl (a nice round number). 


I moved to Hungary and after spending hours converting my blood sugar logs from mg/dl to mmol/L before each doctor's appointment, I finally decided to switch to using mmol/L in my daily life last year. I got used to the new measurements pretty quickly (though I still do sometimes convert the numbers). I was treating lows as anything below 3.9 mmol/L (since 70/18.05=3.87).


At one point my new CDE told me that lows are anything below 3.5 mmol/L (which is 63.17 mg/dl). Magically after that I started not feeling low at 3.7 :-) So I stopped treating the lows unless they are below 3.5. My endo still tries to keep my blood sugars above 4, but considers below 3.5 as the real lows.


But I was wondering about the rest of you who measure in mmol/L -- what is your cut-off for a low blood sugar?

Tags: low, mmol/L

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Here in Holland everything below 4 is a hypo.

We're told by our endo's to stay between 4 - 7, not higher.

Any value above 7 is considered a hyper.


Good luck with this!

I can imagine that it is difficult to switch!

Thanks for all for your responses!


This may be unique to the fact that I was preparing for pregnancy. Non-diabetic pregnant women have lower blood sugar (often in the 60's). I am currently 14 weeks pregnant -- so it is probably OK to treat 3.5 as a low. But after pregnancy, I will go back to 4, especially while taking care of an infant!


Before pregnancy I felt my lows under 4, but during pregnancy I started only feeling them below 3.5.

I don't measure in mmol/L, but I only treat lows below 60. There seem to be 60 people and 70 people, so your 3.5 which is 63 sounds like a good compromise!


I do treat 70 and even in the 70s if it is bedtime. I'm also pretty sensitive to carbs so only need two glucose tabs unless I'm really low when I'll need 3.

Who knows for sure since the modern meters are inaccurate.  I definitely feel it at 3.5 assuming the meter is correct.  I have felt low with 5 using accucheck I am sure it was a bum reading.  It is important to wash hands if you have eaten any fruit something we may forget to do.



 It has been quite a while since I've been on tudiabetes and I've only just seen your prenancy!!! Congratulations! I'm delighted for you! I'm just over 33 weeks myself, hard to believe!

 To answer your original question, I was always told that 4.0 was low until I got pregnant and then was told not to treat them unless under 3.5 since I have been pregnant. Of couse, if I feel low I treat them anyway!

I do not recall reading this ...maybe I missed it ...but for me important to know , how much insulin on board , when I test and show 3.9 ( lower or higher ) ....this will let me treat or not treat . And it depends , what I will do following the test ...just sit or move the body .

I am somewhat concerned , if I am at 3.5 and worry about re-occurring unawareness .As we age and for my security ( and I am over 70 )  , I believe that I need a higher number than 3.5 .

I think that it's also important to have a flexible definition of 'treat'?  If I'm in bed in the middle of the night and hear the bleeping bleeping, I will check and, if it's like 60, I'll just have maybe 6 or 7 jelly beans to avoid a big spike?  If it's lower in the middle of the night, I don't eat more but turn my basal rate down.  Sometimes it will bleep for a while before I catch up but if I eat 15G of carbs, my BG seems to really go up afterwards?  This is kind of true a lot of the time?   If your insulin doses are small and you don't have a lot on board, I think that you can get away with 10G of carbs, rather than the 15/15 recommendation?  If I have 10G and wait 20 minutes, it seems to work pretty well most of the time without the big peaks afterwards.  If I have a load of insulin on board and just whiffed and missed the carbs or something, I'll eat more but I think that there may be a useful advantage to controlling carbs, even when you are lower? 
I agree the 15/15 recommendation is WAY too much for me. I treat with fruit juice or glucose tabs. I have a 50mL measuring cup that I drink out of for lows. I drink 50mL (5g CH) for moderate lows (3.0 to 3.5) and I drink 100mL (10g CH) for lower lows (under 3.0). I only eat something in addition if I have a lot of insulin on board. Then I eat 5-10g of slow acting carbs.

Congratulations on your great expectations!


The 15-20 g carb, retest at 15 minutes is just a guideline--it has to cover a wide range of people, situations, and medications (such as the elderly, people with other serious medical conditions, and children, who often would be advised to avoid the below 70 mg/dl territory as much as possible).


I think the really important part of the guideline is the retest at 15 minutes part, which I am often too lazy to do! That's how we can see how much carb in what types of situations is the best treatment.


For far too many years, I stubbornly refused to acknowledge just how much variation my own body required (different I:C ratio for every meal of the day, different correction factor based on time of day). Now that I've learned I'll just have to live with all the math (thank goodness for calculators!), I'm able to achieve better control. Most days ;-)

The math is certainly a project that is never done!  I am still not 100% sure about the 15 minutes only because when I have OCDiabetic attacks (every other day or so...) I will test at 15 and 20 min after the load of carbs and, even if I only have 7 or 10, the BG still seems to be climbing at the second test, five minutes later?  I try to wait it out a bit longer than the 15 min mostly for that reason?

I had a low this weekend on a long walk (56) took 15g of glucose tabs and 15 minutes later I was 57.  I waited another 15 minutes and I was up to 84 and had climbed to 120 about an hour later.  I always try to wait more than 15 minutes because this pattern is pretty typical for me.



Yet another "your mileage may vary," which pretty much sums up diabetes!




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