Thanks for the tag
@Antje77
I've been T1 for 52 years and over that time my symptoms have changed and got milder.
But I've lost hypo awareness several times, the first two during my pregnancies when I was keeping my bgs low and having a lot of hypos. My poor husband was terrified because I had a night time hypo when I got so low that I was seising on the bed with my eyes rolled back and he wasn't sure whether I was dying. (His account, I have no memory of it).
In general, I found that loss of hypo awareness came whenever I kept my bgs too low and had frequent hypos. After my most recent bad hypo (3 years ago, passed out at the shops, went to A&E) my endocrinologist suggested that I keep my bgs at 6-12 for a while to restore awareness, which worked.
Now that cgms are available I set my dexcom alarm at 4,4 and avoid serious hypos, though if it goes down towards the low 3s I have to use a glucometer to catch how low I actually am, as the dexcom lags a bit.
Question is what happens when my Blood sugars go to low? do i collapse ? lowest its been at night when the alarm goes of is 2.7 yet I feel fine.
I've had readings in the high 2s without issue, but I suspect one's personal "collapse" level might vary, and an under 3 reading is when I tend to panic a bit.
One indicator I used to have is my ability to do maths would disappear when hypo eg try counting down in 7s from 100 and see how easy it is.
I don't know about the autonomic nervous system, I suspect that is something you should ask your team.
I would be very interested in the answer as to whether there is an official "you will pass out at this level" blood sugar level.
And with great reluctance I have to say that alcohol seems to reduce my awareness, at least at the moment.
Not sure if any of the above helps, but I would stress that some people can regain lost hypo awareness.