I have a friend who passes out every time he gets his blood drawn. He's like a deflating balloon.
He's diabetic and has to get blood work done every so often, and he always warns the person taking his blood that he's going to pass out for a second, and it's no big deal, but they always act surprised and panic when it happens.
Yeah, I had to go to therapy for that. What works for me is closing my eyes so I don't get to see the needle or the blood. I still feel a bit weird after but I don't pass out anymore.
Somehow I've never actually fainted but I've had near fainting episodes tons of times. Literally every single time I've been too embarrassed to say anything to anyone or take immediate logical action bahaha! One time when I was a teen at dance class I started feeling that way. Decided to excuse myself to the bathroom. As I was walking down the hall, my vision went black and I had to literally feel for the bathroom door. No idea how I made it in there without fully passing out but it's funny how self conscious I am to do that. I sat on the floor for a few minutes before going back to class. 🙃