A hydrocele is a collection of fluid around the testicle.

What is going on in the body?

A hydrocele may be present at birth or may develop later in life. Most often, a parent notices a swelling in a child's scrotum caused by the hydrocele. The fluid that fills the hydrocele is normally present in the abdomen. It seeps through a balloon-like structure around the testicle called the tunica vaginalis. The neck of this balloon runs along a structure in both of the testes called the spermatic cord and opens into the abdomen. Normally, this neck is sealed off before birth. If it fails to close, fluid continues to seep through and cause scrotal swelling.

What are the causes and risks of the condition?

Hydroceles are more common among premature babies. They develop when the canal between the peritoneal cavity and scrotom fails to close. An inflammation or injury to a testicle may cause a hydrocele.