Infection and testicular pain

A swollen, painful testicle that has come on gradually (perhaps over a few hours or days) is likely to be caused by an infection. This is called epididymo-orchitis. It usually occurs on one side only, but sometimes both sides are affected together. The skin over the testicle may be red and shiny. There may be a discharge from the penis. The cause may be a virus (such as mumps) or various bacteria. It can follow a urine infection, especially in older men. It can also be caused by sexually transmitted bacteria such as chlamydia or gonorrhoea. Obviously, you need to see your doctor as soon as possible for some simple tests and antibiotic treatment, and will need to use a scrotal support.

Both the testicle itself and the epididymis are prone to infection with microorganisms. When both occur together, as they often do, the term is epididymo-orchitis. All cause pain in the area of the testicle, which is tender, swollen and hot to touch. Bacterial infection often descends from the urinary system leading to a typical infection that will normally respond to a course of broad-spectrum antibiotics. The viral infection mumps is not an uncommon cause of orchitis in adult men who are not immune, usually affecting one side, but sometimes both.

Mumps orchitis is usually preceded by facial swelling due to an inflamed salivary gland just below and in front of one or both ears, and because viruses do not respond to antibiotics, the mainstay of treatment is pain relief and rest. In a small proportion of cases, mumps orchitis can lead to infertility if both testicles are involved, although some authorities prescribe corticosteroid medication to minimise inflammation.

If the pain is very severe and has come on suddenly, it is possible that the testicle and its tubing have become twisted within the scrotum (known as 'testicular torsion'. This is most common in adolescents, but can occur at any age. You need to contact your doctor straight away, or go to the nearest hospital emergency department.