Hydrocoeles are fluid-filled bags occurring on one or both sides of the scrotum. They may occur at birth if the passage through which the testicle descends from the abdomen into the scrotum fails to close. Fluid drains from the abdomen into the scrotum where it becomes trapped causing enlargement of the scrotum. Hydrocoeles normally disappear a few months after birth.
Hydrocoeles may also be caused by inflammation or trauma of the testicle. This type of hydrocoele is more common in older men.
Hydrocoeles can be easily demonstrated by shining a flashlight through the enlarged portion of the scrotum. If the scrotum is full of clear fluid, as in a hydrocoele, the scrotum will light up (transillumination).
Hydrocoeles are painless and usually not dangerous. They are mainly treated when they cause discomfort or embarrassment, or if they get so large that they might block the testicle's blood supply. Treatment is either by draining the fluid with a syringe and needle (aspiration) in adults or by a minor surgical procedure that requires little time in hospital.
Sometimes injection of sclerosing (thickening or hardening) medications may be performed after needle aspiration to obliterate (close off) the opening through the scrotal sac, preventing re-accumulation of fluid.
Possible complications after aspiration and sclerosing include infection, fibrosis, and mild to moderate pain in the scrotal area.
Occasionally hydrocoeles may be present together with an inguinal hernia, when some of the intestine also passes down into the scrotum. In this case surgery is needed quickly, to prevent obstruction of the intestine.
Although hydrocoeles are harmless, all swellings in the scrotum need checking to be sure there is nothing more serious going on.
Last Reviewed: 28 May 2009