A couple years ago I took my kids to get a flu shot at a CVS. 30 seconds after my oldest had gotten his shot I felt him go limp standing against me and he collapsed against me and went to the floor. Sheer panic immediately set in and I was on the floor with him calling his name while he ever so slightly convulsed and came to wide eyed 10 seconds later. The CVS employee was the utmost professional, he calmed me down, repeated this is normal, and had me hold his head and legs as he came to. He put my son in a chair, had him sit there for a while and 20 mins later we were in the car. I felt bad when my son actually apologized to me when I told him how terrified I’d been.
I've fainted more times in my life than I'd care to admit. After a while, it's not the 'blood' you are afraid of. Instead it's the idea of fainting and causing a scene that becomes the source of anxiety. For me, anyway.
As a kid I watched the needle go in my arm as blood was drawn.... and all of a sudden tunnel vision and almost fainting. Had to be walked to the car.
So I figured out watching blood come out of me causes me to feel faint, so I don't watch. I've seen blood and other person's blood, but my blood seems to be some special case.
What I've figured out is - if you are bleeding, maybe your brain helps you collapse to the ground in a faint, where you will be level, have a low heart rate, and not bleed out all your blood through a wound.
Could this be the evolutionary reason we faint at the sight of our own blood?
Yep, fainted so, so many times... Always seems to happen after getting hurt on or near a nerve for me - or after a blood draw. Was scary the first time, embarrassing and annoying every time since then. :)
Had a nurse explain that the best way to prevent it is flexing / tightening the legs, to force the blood up out of them. Seems to work, at least for me.
Two of my kids experienced this vasovagal syncope response during injections. It is terrifying; they appear to go into a seizure, convulse, and are unresponsive for up to half a minute. Terrifying.
I became faint, I would say, after I got my first covid shot a couple years ago. It wasn't immediately after the shot but within the 15 minute time frame post-injection when they would have you wait around to see how you feel. It was a strange sensation and there was a place where I was allowed to lie down. I don't know why it happened and it hasn't happened since with further vaccinations. I am glad they were so kind about the whole process.
"researchers have discovered a neural pathway, which involves a previously undiscovered group of sensory neurons that connect the heart to the brainstem. The study, published in Nature on 1 November1, shows that activating these neurons made mice became immobile almost immediately while displaying symptoms such as rapid pupil dilation and the classic eye-roll observed during human syncope."
Very cool. I did not check to see if the authors of this paper are affiialted, but reserchers contributing to data at the NeMO Archive (https://nemoarchive.org/) have recently discovered over 3000 different types of cells in the brain, most of which are in the brain stem. This has added a whole new layer of complexity to explore.
This is interesting in that I never understood that fainting is different than what I'd experienced a number of times through my life. In my case, there's no sensory input but is rather simply low blood pressure (often combined with low blood sugar) and getting up quickly after being very inactive for a long time results in a blackout, fast but gradual fade-to-black and crouching to the ground.
On the other hand, my mother who could be actively busy in the kitchen and talking to me across the room behind her, then if I'm standing close behind her as she turns around surprised to see me standing there, will fall flat on her ass. She doesn't pass out but it's definitely something along the lines of the mechanism described here.
This happened to me recently. I was in the kitchen and decided, for whatever reason, to stretch. There was a drawer open a few feet away. I held the stretch for long enough to induce this blackout, and it went almost exactly as you describe. The next thing I remember is a ten second fade-in to awareness: I'm sideways on the floor making gibberish noises and holding the back of my head. The drawer, now above me, was knocked off its rails. As I reflexively got up from fainting, I did not have awareness of the open drawer, and bonked the back of my head on it.
It was an extremely interesting moment of observing conscious awareness that I think about all the time.
Never fainted but seconds after that I’ve completely lost hearing then tunnel vision started kicking in, and I was 100% certain I’m going to die.
I guess it was the needle shock, eh? The hearing loss was so peculiar though, I remember yelling like crazy and couldn’t even hear my own voice. Scary.
The main thing is that if you feel like you're going to faint, get horizontal as soon as possible. Sitting on the ground is a lot better than sitting in a chair, but lying on the ground is even better and may avoid loss of consciousness - so even if your blood pressure is low for a few seconds, it's still enough to perfuse your brain if there's no hydrostatic gradient.
If someone passes out in a chair, try and gently lie them down on the ground (obviously assuming it's a safe place...) - I've had a few patients who passed out in an airplane seat, and they are often out for much longer with much slower recovery than those who just crumple to the ground and end up horizontal.
Not injection related, but I cleaned a barbell last week (pull from the floor, jump and catch it on your shoulders) and walked it over to the rack on my shoulders, and I felt like I was about to faint after I’d taken 5 steps. Vision started going dark, head got fuzzy and everything. Luckily, I recovered and racked it safely.
It was my own fault I suppose, cleaning so far from the rack, but I wondered what mechanism exactly led to that moment. If I took the bar straight from the rack to my shoulders I could walk around with it no problem, but the clean motion itself probably caused those neurons to activate.
[+] [-] plasma_beam|2 years ago|reply
[+] [-] BrianB|2 years ago|reply
[+] [-] m463|2 years ago|reply
So I figured out watching blood come out of me causes me to feel faint, so I don't watch. I've seen blood and other person's blood, but my blood seems to be some special case.
What I've figured out is - if you are bleeding, maybe your brain helps you collapse to the ground in a faint, where you will be level, have a low heart rate, and not bleed out all your blood through a wound.
Could this be the evolutionary reason we faint at the sight of our own blood?
[+] [-] miriam_catira|2 years ago|reply
[+] [-] leethomas|2 years ago|reply
[+] [-] sethammons|2 years ago|reply
[+] [-] imetatroll|2 years ago|reply
[+] [-] daoboy|2 years ago|reply
Very cool. I did not check to see if the authors of this paper are affiialted, but reserchers contributing to data at the NeMO Archive (https://nemoarchive.org/) have recently discovered over 3000 different types of cells in the brain, most of which are in the brain stem. This has added a whole new layer of complexity to explore.
Exciting times to be involved in neuroscience!
[+] [-] karmakaze|2 years ago|reply
On the other hand, my mother who could be actively busy in the kitchen and talking to me across the room behind her, then if I'm standing close behind her as she turns around surprised to see me standing there, will fall flat on her ass. She doesn't pass out but it's definitely something along the lines of the mechanism described here.
[+] [-] zarmin|2 years ago|reply
It was an extremely interesting moment of observing conscious awareness that I think about all the time.
[+] [-] derefr|2 years ago|reply
[+] [-] Elucalidavah|2 years ago|reply
There's also a "gradual fade-to-white" fainting (vasovagal syncope).
[+] [-] b212|2 years ago|reply
Never fainted but seconds after that I’ve completely lost hearing then tunnel vision started kicking in, and I was 100% certain I’m going to die.
I guess it was the needle shock, eh? The hearing loss was so peculiar though, I remember yelling like crazy and couldn’t even hear my own voice. Scary.
[+] [-] ghufran_syed|2 years ago|reply
If someone passes out in a chair, try and gently lie them down on the ground (obviously assuming it's a safe place...) - I've had a few patients who passed out in an airplane seat, and they are often out for much longer with much slower recovery than those who just crumple to the ground and end up horizontal.
[+] [-] mikrl|2 years ago|reply
It was my own fault I suppose, cleaning so far from the rack, but I wondered what mechanism exactly led to that moment. If I took the bar straight from the rack to my shoulders I could walk around with it no problem, but the clean motion itself probably caused those neurons to activate.