Testicles are the paired glands in the scrotum that make sperm and most of a man’s testosterone. They hang outside the body because sperm prefer a slightly cooler workshop. One often sits lower than the other. That asymmetry is ordinary.

They are tender. A knock takes the breath out of a room. In sex, gentle handling can be pleasurable and rough handling is a specific kink that needs an explicit yes. Monthly self-check for new lumps is unglamorous and useful.

Pain, sudden swelling, or a testicle that rides up and stays painful is urgent care, not a wait-until-Monday problem. Torsion is a clock.