Torsion is a spontaneous twisting of the testicle on the spermatic cord, one or more times.
Incidence of torsion in males under 25 is about 1 in 4000. It is most common in the teenage years.
It more often happens to the left testicle than the right one.
As soon as this occurs the blood flow is blocked, so you have to seek help immediately for your testicle to survive. A salvage rate of 80-100% is found in patients who present within 6 hours of pain. It’s near 0% at 12 hours.

Symptoms
What to do?