How low is low?

Nobody (doctor, nurse, dietician) ever really told me exactly at which point is my BG considered low, requiring to take sugar or something. Anybody?


i was told to treat at 70.

For me, 60's or lower will usually result in me doing something to raise my bg.

Exception can be if I know there's "food already on the way", like right before a meal, in which case I might eat a little more or take a little less bolus with the meal.

I will usually eat a glucose tab when I'm in the 60s and take two or three if I'm in the 50s. Since you're newly diagnosed, you might start using the standard rule of taking 15g of carb if you're under 70. You can fine tune that later as you get more experience.

I was also taught when starting out to have a small snack if I was under 100 (or 110) at bedtime and I still snack up to 100, often by eating 2-4 carbs before going to bed.


Just goes to show we all differ! It seems some people treat below 70 and some below 60. I'm in the second category with the exceptions of before bedtime. I'll treat if I'm in the 70s or lower at bedtime. I agree about fine-tuning, but I think for most of us the 15/15 rule isn't very accurate. I take 2 glucose tabs (8 grams) if I'm in the 50s and three (12) if I'm lower. I also find the waiting time is more like 1/2 hour for me to see the effect.

There's a ton of variables to consider. A big one is how much insulin you have "on board". With a pump it's sort of easy to see (although not always 100%...) but even with shots, you have a shot, you have the "peak", where the insulin is pounding away, either at the food or the elevated BG you are cleaning up but then there's also a "tail" where there's still some "action" going on, pushing your BG down but if there's food pushing back, maybe you're ok and maybe not. I agree that 70s a good frontier but a lot of the people suggesting that are also really doing really well. If it's a 70 with nothing going on, it may be ok to treat mildly but, if it's an hour since your last shot, it may be worth it to consider a bit more treatment, or even food, maybe some protein to boost it for a longer time. When I started making changes to my own thing a few years ago, I'd test and, if I was at 70, I'd test again in like 10 minutes to see what the rate of change was, for experimental purposes. If it was the same, I'd consider it flatter but, if it was 60 or 55 in 10 minutes, I'd figure soemthing heavy was in the works and treat more.

I treat at below 70, but again, it is dependent on so many variables, as acid said. With insulin on board and I have eaten a high fat high protein meal with carbs, I know the carbs will hit me later. I will not treat as long as I am not below 65. I find that in these post meal situations, unless I am exercising or moving about with house work inside, I can float between 65 and 70 for a couple of hours. When the carbs hit in they will raise my sugars, and I have the dual wave running in order to even things out so I do not go high.. I generally always treat below 65, particularly if leaving my home for any reason. Need to have quick reflexes and a rational mid-set when out and about, both of which for me are somewhat compromised when I am running below 65. I also agree with zoe..,I do not need 15 grams of carb for flatline lows in the 60's 3 tabs will do. I need 4 tabs(16 grams) for blood sugars below 60.

God Bless,

Depends on what I'm doing, but I generally treat for anything below 80. It is very easy to overtreat. Unless I'm <60, I just eat something small that I kind of want to eat anyway.

it depends on you- most say below 70. I usually treat in the 60's but now after one scary low I tend to treat in the 70's- 80's if I feel I'm going lower, usually with activity, then I just pop a sweetart or two which is one to two grams and this seems to stop me from going lower

Usually start to feel low at about 70mg or under 4mmols. There are so many variables to take into consideration, as others have mentioned already. I do not feel comfortable at this level without testing every 10mins to see whether I am going up or down further. The only time I can leave this level alone is early in the morning 6-7am when I know it will rise by itself.

The medical community likes to make hard and fast criteria on things like this, but in reality there are a lot of variables. I take no long acting basal, therefore my fasting levels are self regulated and natural. Numbers in the high 60s are not uncommon for me, even without insulin (at least according to my meter, who knows how accurate it is).

I don't get excited about anything above 60 pre-bolus and pre-meal. If I tested two hours after (actually I try to test 1:40 after meals = two hours after bolus) and saw a result below 85 or so, knowing that I still had bolus on board, I'd know that I had better be on high alert and test again in the near future. If I consider myself to have any significant amount of insulin "on board" I would test again if post meal readings are on the low end of normal. Also, would take some comfort knowing I have enough insulin still working if numbers are higher than I might have liked. (again, there are no hard and fast rules, I figure a 3 hour decay for small doses of novolog <3u, longer for larger doses) I don't explain things well, but seems to work for me. Common sense is everything in diabetes management, although they try to spell it out in black and white guidelines that generally don't work well for most of us.

The point at which I treat is 70 mg/dl.

I promply treat anything below 70 mg/dl. Not because of the danger of hypos, but to remain hypo aware. The less time you spend hypo, the less it will "feel normal."

Up until 2 years ago my BS was higher and I would feel lows just under 100. Now I'm on the pump with better control and I'll treat any lows below 70.

My son’s “official” threshold is to treat at 70 or below. Like others have said, we take other factors, such as food/insulin/activity/etc., into account when making that call.

The one thing that was impressed upon me from the beginning is to treat the patient and not rely exclusively the meter. What I mean by that, is that if my son is having low symptoms (usually shaking and light-headedness for him), and his meter says 80, I’m not going to withhold treatment because his meter hasn’t hit that magic number 0f 70. If his meter said 150 when he had those symptoms, I would not treat - I’d give it a little time and retest. A quickly falling bg can cause low symptoms even when he’s not low. In our experience, those symptoms usually subside on their own without treatment as he levels out.

Good luck!

wow, hadnt even thought of taking all of that iob info into account before treating lows! i just see the 70 or less and think, "i want something GOOD!

LOL, i'm with you there! I see low and I start dreaming about what I can eat (so bad.. i'm trying to treat lows with tabs now, to overcome this, i'm doing it, but I'm not saying I like it!)

No easy answers in this game!! Every "low" is different (even in the same person).

I'm in Canada so, of course, we use metric for everything, including our blood sugars. Rather than mg/dl, we use mmol/l. Making the conversion is just a matter of multiplying or dividing by 18.

Below 4 mmol/l (72 mg/dl) is when I treat a low.

I defend, take glucose tabs, at 70 mg/dl. The amount of quick acting carbs depends on IOB and the trend indicated on my CGM. I use anywhere from 4 to 16 grams of quick acting carbs. I do a lot of fingersticks (maybe 4-5/hour) in these situations to try an provide timely and appropriate treatment, but not over-treatment! The CGM lags realtime glucose by about 15 minutes and is not reliable for treatment info beyond its trend indication.

What I mostly want to prevent is the start of my body's counter-regulatory response (emergency glucose release from the liver and secretion of other hormones). Once a counter-regulatory response settles in then I usually experience of high BG bounce that stubbornly resists a quick correction. It often takes hours for me to bring that high BG down.

Speaking of the counter-regulatory response - at what level do those of you under tight control start to have such a response ? (sensations that your body is releasing counter-regulatory hormones such as adrenalin, etc that causes sweating , shaking, nerrvousness, etc).

For me it seems to be below 50.

I'll definitely treat below 70, and sometimes low 70s depending on the IOB and trend.

I am careful not to overtreat.... for me, 1 gram of carb raises BG about 4-5 mg/dl, so one glucose tablet brings me up about 20. I'll calculate how much to bring it back into the 80's and eat that if there is no IOB. Below 60, I don't fool around and eat 15g at once and see what happens before eating more.