As a child develops in the womb, testicles grow near the kidneys in the abdomen.  During the last three months of pregnancy, the testicles move toward their normal place in the scrotum.  To begin their descent, a muscle ring in each side of the groin opens to allow their travel.  The lining of the abdomen accompanies the testicles to line the scrotum and may carry fluid with it. This causes the scrotum to appear enlarged.  Usually this channel closes in most boys and the fluid is absorbed.  This is called a noncommunicating hydrocele.  If it remains open, or reopens, the fluid causes a sac and remains around the testicle(s) in the scrotum.  This is called a communicating hydrocele.  If it opens (or reopens) widely, a part of the intestine can descend through this channel toward the scrotum, ending up as an inguinal hernia.

Injury or inflammation within the scrotum can also produce a hydrocele.  Usually this resolves itself within a few months.  If it remains, medical attention may be required.  Hernias can also develop from straining during bowel movements, coughing, sneezing, heavy lifting or obesity.  These cause pressure on the intestines and can push a section of intestine through a weak spot in the abdomen.

Surgery is recommended for a hydrocele if it is still present in one-year-olds.  Surgery may be required before one year if the scrotum continues to enlarge from fluid build-up.  If the hydrocele is uncomplicated, a simple incision is made to the scrotum so the sac and fluid can be removed.  If it is complicated, such as accompanied by a hernia, a small incision to the groin is made to treat both conditions at the same time.

Hernias should be treated as soon as they are identified.They do not go away on their own. Hernias require suturing (or sewing) of the channel and repair of the muscle ring by a urological surgeon.