Low! How low before one passes out

Yesterday I was a bit late getting lunch. Was out and about with a group of friends. Anyway, had a really bad headache (as I’ve been getting nearly daily). Decided to test.

45! Yikes! Fumbled in my bag and had some honey single serves. Took 2.

Strange. Normally I start to feel shakey between 60 - 70. I felt nothing much, and not shakey. Maybe this is a pregnancy thing as I’m 15 weeks! Scarey!

Was wondering if I was going to pass out. But didn’t feel anything except that headache. And I’ve had that before without being low. How low can one get before passing out?

I passed out once before and don’t know how low I was (besides being unconscious, I was told my meter just read ‘low’.

If I’m not feeling lows I’m not going to be able to rely on how I feel any more and will have to be testing more frequently!

Last night i woke up “not feeling great.” Checked my sugars 20. I have never read that low. Yikes. I had been more active than usual that day and had been grazing at night and despite my insulin pump had managed to stack my insulin. That and I got busy and did not actually eat on of the snacks I had bolused for. Despite 2 glasses of cider my sugars were not budging. I do not recall drinking the first glass of OJ but when my husband handed me a glass he said it was glass #4. Huh? Apparently I was rambling incoherently for about 20 minutes and only semi-conscious. Scared the Bejeebers out of both me and my husband.

I have been having problems picking up lows lately. Seems most times I catch a low it is in the 50’s. I have an appt with the endo tomorrow good timing right? I am going to ask about a CGM.

Low blood sugars are common in the first trimester so please be careful

I’ve seen 11 and 12 on my meters. Not so much recently but I don’t think there’s a number. The paramedics are always like “you were at 47 when we checked” which gets me off on the wrong foot, sort of “what’s the big deal?” with them?

I really think it varies by person. Me, I’ve been in the 30’s before without passing out. The one time I passed out, when I came to I tested and was 38 but have no idea how low I’d been.

Hi Sally,

After a while lows feel less obvious especially if you normally run tight. You may notice something subtle but the signals are much less clear cut they once were. I would test more - having confidence in “where you’re at” is soothing.

Take care,


I haven’t been lower (that I know of) than the low 30s. I can be disoriented, not thinking clearly, shaky - but not pass out. I don’t start to feel symptoms until I’m under 40. TG for the dex!

I agree with Maury - I try to keep my numbers really tight, eat around 30 carbs a day. I don’t think there’s a ‘rule’.

Good job for you and your little one Super Sal!!! I have been standing up, talking( though not very coherently) with a low of 18-19, and at other times a 35 will make me crash!!! I think it depends on the person, the amount of insulin on board… so many different factors. I generally can self-treat with minimal to moderate asssitance until I get under 35 or so; I rarely pass out, but when I do it has been when I was in the low 20’s or teens(or so the paramedics told me).

Fortunately , this does not happen to me very often.

God Bless

People pass out at different numbers. I think some of it may have to do with how fast the drop is? I’ve been fine at 19 (walking around, talking, didn’t feel it)…and felt like I couldn’t move and was sort of slipping off into unconsciousness at about 40.

It really depends for me. I have been in the 40s and felt nothing. I have been in the 60s and felt absolutely horrible (like this morning). I think whether you “feel” a low or not depends on a lot of things, including how much you had to eat before, how much IOB you have, stress, etc. Also, because you’re preggers, I have no idea how that will affect whether you feel a low or not.

No, it’s actually the opposite, Sally! People who have been frequently running high tend to feel low even when they are not technically hypo at all like in the 80s. Hypo unawareness comes about from having frequent lows, and from my understanding can be reinstated by reducing the frequency of lows.

I see people that have been running so high for so long they feel low at 200 mg/dl.

There is no definite number for me. I’ve been 100% conscious and feeling great at 18 and I’ve passed out at 78. It is very rare that I do pass out but I don’t really have a number that once my BG is below it I am in danger of passing out. I try to make sure I am always above 70 and that seems to work for me.

That’s horrific, but makes sense. I suppose such people would have to gradually reduce their ‘average’.

Hypo-unawareness is also caused by autonomic neuropathy. If the hypo-unawareness is caused by AN, then running higher to eliminate the lows will only cause the problem to get worse, not better. In the case of AN, awareness won’t be reinstated. If the cause is from too many lows, then yes, it can be reinstated. Mine is caused by AN so won’t get better.

It varies. I have tested a few times at 13, 17 and 18 and continued walking around. The day the EMTs brought me back around, they tested me at 38. I know I had been low for awhile that night because I was screaming and banging on the walls - it took my neighbors awhile to call 911 and then there was a question of what to do when the cop got here (he was going to leave since I didn’t answer my door). It is possible I was on my way back up by the time they tested me. I agree with Kari that it might have to do with how fast you are dropping.

As long as I’m in good control, I can get down into the 50s before I’m even “low”. I don’t consider 70 low, 80-100 is my target, 70 is fine. I might consider turning off my pump for 30 minutes if I get into the upper 60s. I don’t consider eating anything until the low 60s, then as little as possible - a mint or something.
When I’m going through a bad patch with highs, then 60 begins to get shaky.
I’ve never passed out, or had a seizure. I drove my car right through a red light when I was at 39 a few weeks ago - the worst and only bad incident I’ve had in nearly 25 years. I still swear I didn’t see the light at all.

I have never passed out or had a seizure and I have been as low as 18,20,23. Many mornings I get up with a 45 or 50 and I feel fine. When I get into the low 30’s or 20’s I usually feel tired, weak and get sweaty. Many times my husband can tell I am low before I even realize it. Bless him !!! Everyone is different, but being pregnant, I don’t think you should allow yourself to go too low. Perhaps you should test more frequently to be sure you are in your safe zone.

I agree with everyone else. I have been in the low 20’s and still was able to treat my low, but the one and only time I have passed out I was 39. But I was dropping quickly then. Although after running on my treadmill yesterday I was 37, drank a juice and was fine. So I do believe so many factors go into it as well as how fast you are dropping.

The other thing to be aware of, though, is the accuracy of meters. They are within about 7-10% at the sweet spot (about 100), and the accuracy drops from there. so, a reading of 40 could be anywhere from 30 to 60. I would not trust a reading below 40 to be accurate at all. I would trust that it’s low, just wouldn’t trust how low.

Ive never passed out, but my meter has registered my lowest reading at 24. By the way, I couldn’t see or talk. Thank goodness my wife really likes me!