A hydrocele is a fluid-filled sac that forms in the scrotum causing swelling.
Newborns often have hydroceles but they usually disappear within the first year of life. Older boys and adults can develop hydroceles but they are usually painless and harmless. In some cases hydroceles can be caused by an injury or inflammation in the scrotum
See your GP if you experience any scrotal swelling to rule out any other possible causes. In many cases you may be advised to watch and wait for the hydrocele to go away on its own.