What Is a Hydrocele?

A hydrocele is a condition involving swelling of the scrotum from fluid accumulation that sometimes occurs at birth. It usually affects just one testicle, but a hydrocele can be present on both sides.

When present at birth, the condition often subsides on its own without treatment by the time the baby is a year old. It’s possible for older children and adults to develop a hydrocele, but it’s not as common. Approximately 10% of male newborns are born with a hydrocele; the condition occurs in only 1% of adult males.

In adults, a hydrocele may be acquired through an injury to the groin or after surgery, or through infection. It usually clears up on its own within six months. If a hydrocele does not clear on its own, surgery may be performed.

Types of Hydroceles

There are two different types of hydroceles, including a simple type and a communicating type. A definition of each type of hydrocele includes:

• A communicating type occurs when the tunica vaginalis (a thin sheath that surrounds the testicle) fails to close properly during fetal development. The result is the drainage of fluid from the abdomen into the scrotum.
• A simple type occurs during fetal development when the tunica vaginalis closes, but not before the extra fluid in the testicle can be absorbed.

Hydrocele Symptoms

The symptoms of a hydrocele vary according to the type of hydrocele. For example, a communicating hydrocele will exhibit changes in the size of the testicle, which can vary during the course of a day. This is due to the fluid moving from the abdominal cavity into the scrotum, then being absorbed back into the abdominal cavity.

Simple hydroceles, on the other hand, demonstrate a consistent size (but are larger than normal) throughout the day. They gradually shrink over time.

A hydrocele is located primarily in front of one of the testicles; when palpated (felt), it feels like a small balloon with fluid inside, located inside the scrotum.

Hydroceles (both simple and communicating) do not usually cause any pain, but in adults, particularly if they are large, they may cause some discomfort (from the heaviness of a swollen scrotum) when walking or during sex. The swelling may not be as severe in the morning as it is later in the day.

Causes

To thoroughly understand the causes of a hydrocele, it’s necessary to learn a little about the anatomy of the male reproductive system, namely of the scrotum and testicles.

Pathophysiology

During fetal development, the testicles can be found in the peritoneal cavity (the space inside of the abdomen that contains the intestines, the stomach, and the liver). As the fetus develops, the testicles descend (drop down) through the inguinal canal, into the scrotum.

The inguinal canal is a passageway in the abdominal wall that allows for the passage of the testicles and the spermatic cord (the cord that suspends the testis within the scrotum) in the male.

Because the inguinal canal creates a weakness in the abdominal wall, it is a common area for a hernia to develop. When a hydrocele is suspected, the healthcare provider will usually perform diagnostic tests to rule out a hernia.

Causes in Infants

After the descent of the testicles, the tunica vaginalis (a pouch of serous membranes) is formed to serve as a covering for the testicles. Serous membranes are thin membranes that line internal body cavities.

Normally, there is no communication between the scrotum and the peritoneal cavity (preventing fluid from passing from the abdomen into the scrotum). But when abnormal development occurs in the male fetus, the vaginalis does not close off, and there is a resulting opening that allows abdominal fluid to pass through to the scrotum. In most cases, the underlying cause of this cavity is unknown.

Causes in Adults

Normally, the testicles are surrounded by a protective tissue sac called the tunica vaginalis. This sac produces a very small amount of fluid that allows the testicles to move freely.

Usually, any excess fluid drains off into the veins in the scrotum. However, if there is a disruption in the balance—between the fluid that is produced and the fluid that is drained off—this can result in a hydrocele. Causes of adult hydrocele may include:

• An injury (or other cause of inflammation) to the scrotum
• Spermatic cord blockage
• Inguinal hernia surgery
• Infection of a testicle or of the scrotum

Risk Factors

The primary risk factor for hydrocele in infants is premature birth. Risk factors that occur later in life include:

• Sexually transmitted infections
• Injury to the scrotum
• Inflammation of the scrotum

Diagnosis

A physical examination of a newborn may reveal the presence of a hydrocele. The diagnostician (usually a pediatrician) may shine a light through the swollen scrotum (a procedure called transillumination), which may reveal clear fluid surrounding the testicle. If a hydrocele is present, the testicle will appear to be filled with a clear fluid.

If any tissue in addition to the testis is discovered inside the testicle, it may be a sign of a hernia. The examination will most likely include:

• Checking for any type of enlargement or tenderness of the scrotum
• Applying pressure to the abdomen to check for an inguinal hernia
• Observing to see if the bulge in the groin area changes when a patient coughs (which increases pressure in the area).

Other diagnostic measures may include blood or urine tests to check to ensure there is no infection present, such as epididymitis, which is an inflammation of the coiled tube located at the posterior (back) side of the testicle.

Magnetic resonance imaging (MRI) or a scrotal/pelvic ultrasound may be performed to evaluate the severity of the hydrocele and rule out the presence of a hernia.

Imaging tests may also include a computerized tomography (CT) scan. This is an imaging test that takes a series of pictures from various angles, producing X-ray images with detailed illustrations of various body parts. A dye may be swallowed or injected before the procedure to enable the organs or tissues to show up more clearly.   

MRI is an imaging technique that uses a strong magnetic field and radio waves to generate very detailed images of areas inside the body. An MRI can show some diseases that are invisible using a CT scan.

Treatment

Treatment is not always required for a hydrocele that is present at birth, because it often clears up on its own by the time the baby is a year old. In adults, however, treatment modalities may include:

• Pain medication to alleviate any pain or discomfort
• Surgery to remove tissue, such as in a hernia, or to repair the hydrocele (usually for a communicating hydrocele)
• Surgery to remove some of the fluid and alleviate the swelling in large or infected hydroceles

Surgery may involve a small incision in the scrotum or groin area, near the scrotum, to drain out the accumulated fluid; it is usually considered a minor procedure that can be performed on an outpatient basis. A person is likely to go home the same day the procedure is done.

A hydrocelectomy (removal of a hydrocele) is considered the treatment of choice when a hydrocele does not subside on its own, becomes too large, or causes pain. But surgery can result in several complications, including:

• Hematoma (bleeding into the tissue)
• Infection
• Persistent swelling
• Chronic (long term) pain
• Testicular atrophy (shrinkage)
• Recurrence of the hydrocele
• Repeat surgical treatment to drain the hydrocele if it is painful, large, or infected

Aspiration (removal of fluid with a needle) is not frequently used today, but in some instances (such as in a person with a heart condition who is taking blood thinners), a needle aspiration procedure may be performed to remove fluid. The hydrocele may re-occur following aspiration, and may require repeat aspiration or surgical procedure.

Surgical Treatment Study

A 2019 study described a new method utilizing individualized minimally invasive surgery (which involved a smaller incision and shorter surgery time) that was found to be effective for treating a hydrocele.

In addition, the study subjects who received minimally invasive surgery (instead of traditional surgery) for a hydrocele did not experience serious complications, such as recurrent hydrocele, chronic scrotal pain, or testicular atrophy (shrinkage of the testicles) during an average follow-up period of 12 months.

Further, hydrocele repair may be done microsurgically to avoid damage to surrounding tissue, including the vas deferens (sperm transport tube).

Prognosis

The prognosis for hydrocele treatment is good. The condition is not usually dangerous unless it is very large or becomes infected.

After surgery, a jockstrap is worn for a few weeks to keep the scrotum elevated, which helps to reduce swelling. Howver, it may take several months for the swelling to completely subside. The hydrocele may return once it subsides, even after surgery.

A Word From Verywell

A hydrocele is not usually a serious condition, but in some instances, it may cause pain or discomfort. Surgical treatment for a hydrocele is considered a simple procedure, but because there is a high likelihood of recurrence of a hydrocele (or other complications,) it’s important to do your research: consult with your healthcare provider and consider your options before getting treatment.