In my case, I haven't suffered serious injuries in my life. The one with the hardest emotional impact happened when I was a child and I accidentally introduced my finger in a vertical fan. It looked something like this:
I remember crying a lot and there was also a lot of blood, but the only consequence was a small injury that looked like a raisin.
The only time I needed stitches happened many years later. It was about 3 or 4 years ago. I was opening a can of tuna, and the same middle finger was cut open by the can. I didn't even feel the injury but once I saw the blood coming out of my finger I realized what had happened. I went to a clinic and it only needed 1 stitch. I now have a small scar as a result of this little accident.
What was the worst injury you have suffered? Was it an accident or perhaps you were the victim of a physical assault?