When does one go 'out' from a low?

[BriOnH]

I haven't had a hypo I couldn't get out of in over 15 years, but when I did have hypos I couldn't get out of and my mom tested me I was once 35, and another time 42 (the two times she was able to get a test in while my dad was giving me glucagon). So my question is this:
Does anyone know what causes a hypo where you black out, or cant walk, or just basically cant function? I've been 11 mg/dl before and still concious, and numerous other times where i have been in the 30-50 range, also still concious, so I find it weird that at 35 and 42 I would be out. Maybe its being that low for a long period of time? I have always wondered about this.
-Brian

[Cinnabon]

Blood glucose levels drop rapidly as cells absorb all available sugars and brain cell starvation occurs that can lead to coma.
I have been at 22 and it causes seizures as well.

[JasonSmithMT]

Unfortunately there is no definitive glucose level where one can say that loss of consciousness occurs. Like most things in medicine it is dependent on many individual factors and will vary within a individual on a case basis.

The reason hypoglycemia can cause loss of consciousness is a result of central nervous system neuronal glucose deprivation (UGH!). That is the brain doesn't get enough glucose to function properly. Medical folk like to call this neuroglycopenic symptoms. It comprises one of the two major categories of hypoglycemic symptoms. Neuroglycopenic symptoms include confusion, fatigue, and seizure. The other major group is the autonomic symptoms. These include things like palpitations, tremor, anxiety, sweating, and hunger. These are a result of the release of epinephrine, norepinephrine, and acetlycholine.

Jason

[Funnygrl]

It has to do with the glucose level, the amount of time it dropped over, how high you were before it dropped, and how many lows you've had before. If your body is not used to lows, or you dropped fast, you are more likely to pass out quickly.

I've passed out from lows twice. The first time my bs was 18, the second time my bs was 45. The second time my bses leading up to the incident had been running higher.

Right now I am pretty hypo unaware. My bs has been 20s several times and I've been okay enough to give myself glucagon, since food was not bringing it up.