Orchitis is a condition that is characterized by inflammation in one or both of the testicles. It is most often caused by a bacterial infection or by the mumps virus. Orchitis is also known as epididymo-orchitis, a testis infection, testicular inflammation or swelling. Ever since the MMR vaccine, orchitis has become much less common. This is because the MMR (Measles, Mumps, and Rubella) vaccine works by preventing the mumps virus. Still, orchitis occurs in about 20 to 35 percent of boys and men who develop the mumps virus.

If orchitis is caused by a bacterial infection, it may have been caused by a sexually transmitted infection. Types of sexually transmitted infections that may cause orchitis include chlamydia or gonorrhea. Other things that may cause bacterial orchitis include epididymitis. When orchitis is caused by epididymitis, it is called epididymo-orchitis. Epididymitis is an inflammation of the epididymis which is located at the back of the testicle and is responsible for storing and carrying sperm. 

The signs and symptoms of orchitis usually appear pretty quickly. They often include swelling in one or both testicles, pain that ranges from mild to severe, tenderness in one or both testicles which may last for weeks, fever, nausea and vomiting.

There are two sets of risk factors for developing orchitis. There are risk factors for nonsexually transmitted orchitis and there are risk factors for sexually transmitted orchitis. Nonsexually transmitted orchitis are risk factors that are not related to a sexually transmitted infection and they include not being immunized against mumps, having recurring urinary tract infections, having surgery that involves the genitals or urinary tract, or being born with an abnormality in the urinary tract.

The risk factors for sexually transmitted orchitis are associated with certain behaviors that can increase your risk of developing a sexually transmitted infection which can cause orchitis. These risk factors include having multiple sexual partners, sex with a partner who has a sexually transmitted infection, having unprotected sex without a condom, or having a personal history of having a sexually transmitted infection.

Treatment for orchitis depends on what caused it such as either a bacterial infection or a virus. Depending on what caused the orchitis treatment might include antibiotics to clear up the infection, anti-inflammatory medication to reduce the swelling, pain medication, cold packs and rest. The best was to prevent orchitis is to get the MMR vaccine to be immunized against mumps. Mumps is the most common cause of viral orchitis. Otherwise, make sure to practice safe sex by using condoms to protect against STIs which can cause bacterial orchitis.