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 for orchitis typically involves managing symptoms, such as using pain relievers and applying ice packs. In cases caused by bacterial infections, antibiotics may be prescribed. It's important to seek medical attention if symptoms arise, as untreated orchitis can lead to complications, including fertility issues.