I've recently had this experience. I fell off of a horse. The saddle shifted and I couldn't extricate my foot from the stirrup. I was in pain and passed out three times in the barn. Three weeks later I am healing.
No broken bones. I was lucky.
Years ago I had three incidents. Once on a public train going to work with the flu.
The other, staying up too late and eating too many sweets.
The third spraining my ankle on a staircase carrying too many instruments down it. I don't do pain well.
Fainting may well be a protective aspect of the body. It fights pain and bodily abuse.
When I had a heart problem years ago (blockages in arteries calling for a angioplasty) I did not faint.
These are my experiences. Otherwise I have been told by my doctor that I am healthy.