Inflammation of one or both testicles, the organs lying in the scrotum which produce sperm. Testicular inflammation usually occurs in combination with epididymitis. A rapid onset of testicular inflammation may be caused by an infection of the urinary tract, prostatitis, epididymitis , during an attack of mumps, as a result of the venereal disease gonorrhoea and other infectious diseases in which bacteria can reach the testicles via the blood, and as a result of accidents in which the testicle is damaged. Testicular inflammation causes the scrotum to swell, and is very painful. The same symptoms also occur with torsion of the testicle, and here surgical treatment is necessary. With children, inflammation occurs mainly during mumps, and mumps can cause testicular inflammation in adults too.