Epididymitis (ep-ih-did-uh-MY-tis) is an inflammation of the coiled tube (epididymis) at the back of the testicle that stores and carries sperm. Males of any age can get epididymitis. Epididymitis is most often caused by a bacterial infection, including sexually transmitted infections (STIs), such as gonorrhea or chlamydia.
https://www.mayoclinic.org/diseases-conditions/epididymitis/symptoms-causes/syc-20363853