Epididymitis is a medical condition when pain in of the epididymis, a curved structure at the back of the testicle where sperm matures and is stored. Epididymitis is usually either acute or chronic: if acute, the onset of testicular pain is often accompanied by inflammation, redness, and warmth in the scrotum: if chronic, pain may be the only symptom. In either form, testicular pain in one or both testes can vary from mild to severe, and one or both epididymides may noticeably swell and/or harden. The pain may last from less than an hour to several days. Antibiotics are usually the choice of treatment.