Cause and Risk Factors for Hydrocele

Hydroceles are caused by the accumulation of fluid in the scrotum, surrounding one, or less often both, of the testes. In most cases, the condition is congenital—or present at birth.

Before birth, the testicles develop in the abdomen. A few weeks before the baby boy is born, they descend connected to a tube (called the processus vaginalis) to the scrotum. When this movement is complete, the tube usually closes.

When the tube does not close, fluid from the abdomen can collect in the scrotum, causing a communicating hydrocele. This condition is called "communicating" because the pathway between the abdomen and scrotum is wide open. This type of hydrocele is typically bigger in the evening and smaller, or absent, in the morning as the fluid often returns to the abdomen after lying down.

Non-communicating hydroceles occur when fluid stays inside a closed sac and is not gradually absorbed into the body. Men (especially over the age of 40) can develop non-communicating hydroceles as a result of an infection or injury to the scrotal area, or if blood or fluid becomes blocked inside the spermatic cord. Most non-communicating hydroceles, however, seem to occur for no apparent reason.

In adult males, radiation therapy (e.g., used to treat prostate cancer) can increase the risk for developing a hydrocele.

Publication Review By: William Belville, M.D., Stanley J. Swierzewski, III, M.D.

Published: 22 Jul 2007

Last Modified: 22 Sep 2015