A hydrocele (HI-droe-seel) is a type of swelling in the scrotum that occurs when fluid collects in the thin sheath surrounding a testicle. Hydrocele is common in newborns and usually disappears without treatment by age 1. Older boys and adult men can develop a hydrocele due to inflammation or injury within the scrotum.
A hydrocele usually isn't painful or harmful and might not need any treatment. But if you have scrotal swelling, see your doctor to rule out other causes.
Usually, the only indication of a hydrocele is a painless swelling of one or both testicles.
Adult men with a hydrocele might experience discomfort from the heaviness of a swollen scrotum. Pain generally increases with the size of the inflammation. Sometimes, the swollen area might be smaller in the morning and larger later in the day.
When to see a doctor
See your doctor if you or your child experiences scrotal swelling. It's important to rule out other causes of the swelling that might require treatment. For example, a hydrocele might be associated with a weak point in the abdominal wall that allows a loop of intestine to extend into the scrotum (inguinal hernia).
A baby's hydrocele typically disappears on its own. But if your baby's hydrocele doesn't disappear after a year or if it enlarges, ask your child's doctor to examine the hydrocele again.
Get immediate medical treatment if you or your child develops sudden, severe scrotal pain or swelling, especially within several hours of an injury to the scrotum. These signs and symptoms can occur with a number of conditions, including blocked blood flow in a twisted testicle (testicular torsion). Testicular torsion must be treated within hours of the beginning of signs and symptoms to save the testicle.
A hydrocele can develop before birth. Normally, the testicles descend from the developing baby's abdominal cavity into the scrotum. A sac accompanies each testicle, allowing fluid to surround the testicles. Usually, each sac closes and the fluid is absorbed.
Sometimes, the fluid remains after the sac closes (noncommunicating hydrocele). The fluid is usually absorbed gradually within the first year of life. But occasionally, the sac remains open (communicating hydrocele). The sac can change size or if the scrotal sac is compressed, fluid can flow back into the abdomen. Communicating hydroceles are often associated with inguinal hernia.
A hydrocele can develop as a result of injury or inflammation within the scrotum. Inflammation might be caused by an infection in the testicle or in the small, coiled tube at the back of each testicle (epididymitis).
Most hydroceles are present at birth. At least 5 percent of newborn boys have a hydrocele. Babies who are born prematurely have a higher risk of having a hydrocele.
Risk factors for developing a hydrocele later in life include:
Injury or inflammation to the scrotum
Infection, including a sexually transmitted infection (STI)
A hydrocele typically isn't dangerous and usually doesn't affect fertility. But a hydrocele might be associated with an underlying testicular condition that can cause serious complications, including:
Infection or tumor. Either might reduce sperm production or function.
Inguinal hernia. The loop of intestine trapped in the abdominal wall can lead to life-threatening complications.