I've had a few testicular torsions. The first one, which was also the worst, happened when I was working my job video store. My pants were probably tighter than I like them now, but I was at an age where I was trying to show off a lot. The store was empty and it was a little before closing. My boss told me to mop the floor and then I could go home for the night.
While I was mopping I guess I bent down and turned in a way that, combined with tighter pants, caused one of my testicles to twist 180 degrees, cutting off blood flow. It felt like I had been hit in the lower abdomen with a sledge hammer and I couldn't really stand or walk normally. Fortunately, I was able to leave right afterwards, but I could barely even sit down in my car because having my balls rest on the seat was intensely painful, but I managed to get home alright.
When I got home, I was still living with my parents, I sat down at the family computer and started talking to a girl I met online that I had been talking to for a few years. I told her about how much pain I was in, and sitting on a wooden chair was making it worse. I started feeling pretty lightheaded from the pain and decided to lie down on my bed for awhile.
Maybe 15 minutes later my mother walked by my room and saw me passed out on my bed with the door open and she said my skin looked grey. I explained what was happening and how much pain I was in. My parents wanted to take me to the emergency room but I refused. My mother, who is a nurse asked me if I wanted to have my father take a look, which I also refused. They also asked about discoloration or swelling and I explained that I was in so much pain that I couldn't even take my pants off to check.
I was extremely lucky that I didn't lose my testicle. Somehow it corrected itself, or maybe I did something subtle to fix it, but a few days later I went to the doctor and they didn't believe that I had a torsion because he didn't think I would be able to fix it. He sent me to a urologist for follow up and to see if there was any damage. I got an ultrasound which showed that there was no permanent damage. The urologist suggested that I get surgery to have my testicles sutured together to prevent it from happening again. I refused that as well.
I've had torsions several times since then, but the pain was less severe and I was able to learn how to correct it, though I'm sure I just got lucky. Over time they seem to have become less and less common. In my late teens and early twenties it happened at varying degrees somewhat often. It still happens much less often and much less severe, like a 90 degree twist instead of 180, still painful but not nearly as bad.