Testicular torsion happens when the spermatic cord twists, cutting off blood to the testicle. It strikes fast—often in the middle of the night or after a minor bump—and is a true emergency. Sudden, severe pain is the hallmark. It feels like someone kicked the ball and the ache keeps climbing, usually on one side only. Swelling is quick. The scrotum puffs within minutes and looks red or purple. The testicle rides high. One ball hangs sideways or tilts like a bell clapper and can’t be eased down. Nausea and vomiting ride along. The pain triggers a sick stomach and can... Learn more