I can get vasovagal syncope from damn near anything that I get sufficiently freaked out about, including having blood drawn or severe pain. Honestly, it’s usually better if I fully pass out - then when I wake up I’m confused and flushed and might throw up, but I actually don’t feel that terrible. The incidents where I almost lose consciousness leave me with a terrible headache, and I still usually end up throwing up.
I once felt strongly enough about giving blood that I decided I should “man up” and just go do it. I passed out while donating, but the Red Cross still called me about once a month for the next 6 months to ask if I would donate again
