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.
It's been 2 years since my last episode and now I don't feel that anxious anymore, but it feels like there is something in the back of my mind telling me that it can happen again.
Luckily I only fainted a few times in my life but the last one was most vivid as in some time had clearly passed and I was injured. That scares me now thinking under what circumstances it could happen again.
Fainted for the first time, because of a nose bleed, in front of my high school physics class, literally.
My wife has had to these for years. The only treatment we’ve found helpful is transcutaneous vagus nerve stimulation (tVNS) with a tool like a Neuvana Xen - or you can go the expensive prescription route. We were actually treating her gastroparesis with this and found that modulating the signal worked for all sorts of misfirings - like when getting shots.
TLDR: You can’t avoid them, but you can mitigate them by sitting in a chair, leaning back, and bringing your feet closer to your heart. If anyone is watching, it just looks like you are trying out the recline function of the chair. If your Vagus Nerve issues are bad, you can try tVNS (under the supervision of your doctor, of course).
https://my.clevelandclinic.org/health/body/21778-nose
There is a number of sinus decongesting massage moves that work well. These use pressure and blood flow to force the liquid out of your sinuses and then uses gravity to take it away. I use these to help relieve sinus pressure.
https://health.clevelandclinic.org/sinus-massage/
But, to answer the original question, this is only related tangentially. Laying down, picking up your feet, and breathing generates a signal in your Vagus Nerve complex that essentially overrides the fainting signal. It’s still there, but you’ve added a new stronger signal to dominate the nerve and the fainting signal starts to fade. Simple meditative breathing does the same, but usually not fast or strong enough to stop you from syncope.
https://health.clevelandclinic.org/what-does-the-vagus-nerve...
Oh, no; the motion I'm referring to doesn't involve moving my head at all. I meant that I raise my right knee while balancing on my left leg, to scrub my right calf by bringing it into reach. (Is this not how most people clean their legs in the shower?) Doing this — and holding the pose for at least a few seconds — almost always unplugs my right sinus. (And only the right sinus. Have to raise my left leg to unplug my left sinus!)