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.
Your doctor will start with a physical exam. It's likely to include:
Checking for tenderness in an enlarged scrotum.
Applying pressure to the abdomen and scrotum to check for inguinal hernia.
Shining a light through the scrotum (transillumination). If you or your child has a hydrocele, transillumination will show clear fluid surrounding the testicle.
After that, your doctor might recommend:
Blood and urine tests to help determine if you or your child has an infection, such as epididymitis
Ultrasound to help rule out hernia, testicular tumor or other causes of scrotal swelling
In baby boys, a hydrocele sometimes disappears on its own. But for males of any age, it's important for a doctor to evaluate a hydrocele because it can be associated with an underlying testicular condition.
A hydrocele that doesn't disappear on its own might need to be surgically removed, typically as an outpatient procedure. The surgery to remove a hydrocele (hydrocelectomy) can be done under general or regional anesthesia. An incision is made in the scrotum or lower abdomen to remove the hydrocele. If a hydrocele is found during surgery to repair an inguinal hernia, the surgeon might remove the hydrocele even if it's causing no discomfort.
After hydrocelectomy, you might need a tube to drain fluid and a bulky dressing for a few days. Your doctor is likely to recommend a follow-up exam because a hydrocele might recur.
Preparing for an appointment
You might be referred to a doctor who specializes in conditions of the urinary and reproductive tract (urologist). Here's some information to help you get ready for your appointment.
What you can do
List symptoms you or your child has had and for how long
List all medications, vitamins and supplements you or your child takes, including the doses
List key personal and medical information, including other conditions, recent life changes and stressors
Prepare questions to ask your doctor
For hydrocele, some basic questions to ask your doctor include:
What do you think is causing this swelling? Are there any other possible causes?
What kinds of tests are needed?
What treatment do you recommend, if any?
What signs or symptoms will indicate that it's time to treat this condition?
Do you recommend any restrictions on activity?
Don't hesitate to ask other questions that arise during your appointment.
What to expect from your doctor
Your doctor is likely to ask you a number of questions.
If your child is affected, your doctor might ask:
When did you first notice this swelling? Has it increased over time?
Is your child in any pain?
Does your child have any other symptoms?
If you're affected, your doctor might ask:
When did you first notice the swelling?
Have you had any discharge from your penis or blood in your semen?
Do you have discomfort or pain in the affected area?
Do you have pain during intercourse or when you ejaculate?
Do you have a frequent or urgent need to urinate? Does it hurt when you urinate?
Have you and your partner been tested for STIs?
Do your hobbies or work involve heavy lifting?
Have you ever had a urinary tract or prostate infection or other prostate conditions?
Have you ever had radiation or surgery in the affected area?
What you can do in the meantime
If you are a sexually active adult, avoid sexual contact that could put your partner at risk of contracting an STI, including sexual intercourse, oral sex and any skin-to-skin genital contact.