Hydroceles are common in newborn males. During development the testicles descend from the abdomen to the scrotum down a tract known as the processus vaginalis. When this tract fails to close after their descent, the scrotum can fill with fluid from the abdomen. This situation usually resolves within a few months. In men, hydroceles can result from inflammation in their reproductive system, from injury or from an obstruction in the spermatic cord.
Spermatoceles arise from an accumulation of sperm, usually in the head of the epididymis. The reasons for this accumulation are not well known. In many instances they appear to occur spontaneously without any preceding instances of injury, infection or inflammatory conditions. Research is pursuing the origins of spermatoceles.