A hydrocele is a fluid-filled sac surrounding a testicle that results in swelling of the scrotum, the loose bag of skin underneath the penis. Older boys and adult men can develop a hydrocele due to inflammation or injury within the scrotum.

A hydrocele usually isn't painful. Typically not harmful, a hydrocele may not need any treatment. However, if you have scrotal swelling, see your doctor to rule out other causes.

They are common in newborns, but most hydroceles disappear without treatment within the first year of life. However, if your baby's hydrocele doesn't disappear after a year or if it enlarges, you should make another appointment for your child's doctor to examine the hydrocele again.

Symptoms

Usually the only indication of a hydrocele is a painless swelling of one or both testicles. Adult men with a hydrocele may experience discomfort from the heaviness of a swollen scrotum. Sometimes, the swollen testicle may be smaller in the morning and larger later in the day.

See your doctor if you experience scrotal swelling. It's important to rule out other possible causes for the swelling. Sometimes a hydrocele is associated with an inguinal hernia, in which a weak point in the abdominal wall allows a loop of intestine to extend into the scrotum and which may require treatment.

Causes

In older males, a hydrocele can develop as a result of inflammation or injury within the scrotum. Inflammation may be the result of infection of the small coiled tube at the back of each testicle (epididymitis) or of the testicle.

A hydrocele typically isn't dangerous and usually doesn't affect fertility. However, it may be associated with an underlying testicular condition that may cause serious complications:

• Infection or tumor. Either may reduce sperm production or function.
• Inguinal hernia. A loop of intestine could become trapped in the weak point in the abdominal wall (strangulated), a life-threatening condition.

Get immediate medical treatment if you 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 hydrocele. These signs and symptoms may also be caused by a condition called testicular torsion. Testicular torsion is an emergency medical condition that occurs when a testicle becomes so twisted that blood flow is blocked. The testicle can only be saved if this condition is treated within hours of when symptoms began.

If you have painless scrotal swelling, meet your doctor.

Tests and diagnosis

Your doctor will do a physical exam. The exam may reveal an enlarged scrotum that isn't tender to the touch. Pressure to the abdomen or scrotum may enlarge or shrink the fluid-filled sac, which may indicate an associated inguinal hernia.

Because the fluid in a hydrocele usually is clear, the doctor may shine a light through the scrotum (transillumination). With a hydrocele, the light will outline the testicle, indicating that clear fluid surrounds it.

If your doctor suspects your hydrocele is caused by inflammation, blood and urine tests may help determine whether you have an infection, such as epididymitis.

The fluid surrounding the testicle may keep the testicle from being felt. In that case, you may need an ultrasound imaging test, can rule out a hernia, testicular tumor or other cause of scrotal swelling.

Treatments and drugs

For adult males as well, hydroceles often go away on their own within six months. A hydrocele requires treatment only if it gets large enough to cause discomfort or disfigurement. Then it may need to be removed.

Treatment approaches include:

• Surgical excision (hydrocelectomy). Removal of a hydrocele may be performed on an outpatient basis using general or spinal anesthesia. The surgeon may make an incision in the scrotum or lower abdomen to remove the hydrocele. If a hydrocele is discovered during surgery to repair an inguinal hernia, your doctor may remove it even if it's causing you no discomfort.

A hydrocelectomy may require you to have a drainage tube and wear a bulky dressing over the site of the incision for a few days after surgery. Also, you may be advised to wear a scrotal support for a time after surgery. Ice packs applied to the scrotal area after surgery may help reduce swelling. Surgical risks include blood clots, infection or injury to the scrotum.

• Needle aspiration. Another option is to remove the fluid in the scrotum with a needle. The injection of a thickening or hardening (sclerosing) drug after the aspiration may help prevent the fluid from reaccumulating. Aspiration and injection may be an option for men who have risk factors that make surgery more dangerous. Risks of this procedure include infection and scrotal pain.
Sometimes, a hydrocele may recur after treatment.