Orchitis is an inflammation of one or both testicles, often caused by infections, such as viral infections like mumps or bacterial infections. Symptoms may include swelling, pain, and tenderness in the affected area, along with fever and general discomfort. Treatment typically involves managing symptoms with pain relievers and, in some cases, antibiotics if a bacterial infection is present. Most cases of orchitis resolve without complications, but it is important to seek medical attention to prevent potential issues, such as infertility or abscess formation.