Hydrocele in Children: Causes, Symptoms & Treatment

What Is a Hydrocele in Children?

A hydrocele is a fluid-filled sac surrounding one or both testicles that causes painless scrotal swelling in boys. It occurs when fluid accumulates in the thin membrane (tunica vaginalis) that surrounds the testicle. Hydroceles are common in newborns and typically resolve spontaneously within the first two years of life.

The term "hydrocele" comes from the Greek words "hydro" (water) and "kele" (tumor or swelling), literally meaning "water tumor." While the name may sound concerning, a hydrocele is a completely benign condition that poses no threat to your child's health, development, or future fertility. It is simply a collection of clear fluid around the testicle that causes the scrotum to appear enlarged.

Hydroceles are remarkably common in newborn boys, occurring in approximately 1-2% of male infants. The condition is even more prevalent in premature babies, where the incidence can be as high as 16-25%. This higher rate in preterm infants is directly related to the developmental process that occurs before birth, when the testicles descend from the abdomen into the scrotum.

During fetal development, the testicles form inside the abdomen and gradually migrate down through the inguinal canal into the scrotum during the third trimester. This migration creates a small opening called the processus vaginalis, which normally closes before or shortly after birth. When this opening fails to close completely, fluid from the abdominal cavity can accumulate around the testicle, creating a hydrocele.

Types of Hydroceles

Understanding the type of hydrocele your child has is important because it affects both the prognosis and potential treatment approach. There are two main types of hydroceles in children:

Communicating hydrocele: This type occurs when the processus vaginalis remains open, creating a direct connection between the abdominal cavity and the scrotal sac. As a result, abdominal fluid can flow freely in and out of the hydrocele. A key characteristic of communicating hydroceles is that they change in size throughout the day – the swelling typically increases when the child is upright or active (due to gravity and increased abdominal pressure) and decreases when the child is lying down or sleeping. Communicating hydroceles are more commonly associated with inguinal hernias because the same opening that allows fluid to pass can also allow bowel to protrude into the scrotum.

Non-communicating hydrocele: This type occurs when the processus vaginalis has closed but some fluid became trapped around the testicle during the closure process. Because there is no connection to the abdominal cavity, the fluid cannot drain, and new fluid cannot enter. The size of a non-communicating hydrocele remains relatively constant and does not change significantly with position or activity. This type of hydrocele often resolves as the trapped fluid is gradually reabsorbed by the body over time.

What Are the Symptoms of Hydrocele in Children?

The primary symptom of hydrocele is painless swelling of the scrotum on one or both sides. The swelling appears as a smooth, soft bulge that can range in size from small (olive-sized) to large (plum-sized or larger). Unlike other scrotal conditions, hydrocele does not cause pain, tenderness, or discomfort in the child.

Recognizing a hydrocele in your child is usually straightforward because the main symptom – scrotal swelling – is visually apparent. However, understanding the full range of characteristics associated with hydroceles can help you distinguish this benign condition from other scrotal abnormalities that may require more urgent attention.

The most common presentation is unilateral (one-sided) scrotal swelling, meaning only one testicle is affected. However, bilateral hydroceles (affecting both testicles) occur in approximately 10-15% of cases. The swelling typically has a characteristic appearance – it is smooth, round or oval-shaped, and has well-defined borders. When you gently touch the swelling, it feels soft and fluid-filled, similar to a water balloon.

One of the hallmarks of a hydrocele is that it is completely painless. Your child should show no signs of discomfort when the area is touched or during normal activities like diaper changes, bathing, or movement. The testicle itself remains normal within the fluid collection and continues to develop properly. Parents often discover the hydrocele during routine diaper changes or bathing when they notice that the scrotum appears larger or more swollen than usual.

Key Signs to Look For

• Scrotal swelling: Visible enlargement on one or both sides of the scrotum
• Soft, fluid-filled feel: The swelling feels squishy rather than hard when gently touched
• No pain or tenderness: Your child shows no discomfort when the area is touched
• Smooth surface: The swelling has a uniform, smooth appearance without lumps or irregularities
• Size variation (communicating type): Swelling that increases during the day and decreases after rest
• Normal behavior: Your child feeds, sleeps, and behaves normally despite the swelling

Size Variations

Hydroceles can vary considerably in size, and the size may fluctuate over time. Small hydroceles may only cause minimal swelling that is barely noticeable, while larger ones can cause significant scrotal enlargement. Healthcare providers sometimes describe hydrocele size using common comparisons: a small hydrocele might be olive-sized, a medium one might be the size of a plum, and a large hydrocele might approach the size of a small orange.

It's important to note that the size of the hydrocele does not correlate with the severity of the condition or the need for treatment. Even large hydroceles are typically harmless and may resolve spontaneously. The decision to pursue treatment is based more on persistence over time rather than size alone.

When Should You See a Doctor for Scrotal Swelling?

See a doctor for routine evaluation if your child develops new scrotal swelling that was not present at birth. Seek immediate medical attention if your child has sudden severe pain, redness or discoloration, fever, vomiting, or if the swelling is hard rather than soft – these may indicate testicular torsion, which is a medical emergency.

While hydroceles are benign and typically resolve on their own, it's important for any scrotal swelling in a child to be evaluated by a healthcare provider. This ensures proper diagnosis and helps rule out other conditions that may require more urgent treatment. The timing and urgency of seeking medical care depends on the specific symptoms your child is experiencing.

If you notice scrotal swelling in your newborn that was not previously documented at birth, it's appropriate to schedule a routine appointment with your child's pediatrician within a few days to a week. This allows for proper examination and documentation, even though the condition is likely harmless. If your child is older and develops new scrotal swelling, a similar timeline applies – routine evaluation within a reasonable timeframe.

However, certain symptoms require immediate medical attention because they may indicate more serious conditions such as testicular torsion (twisting of the testicle that cuts off blood supply) or incarcerated inguinal hernia (bowel trapped in the scrotum). These conditions are medical emergencies that require prompt treatment to prevent permanent damage.

Routine Evaluation Indications

Schedule a non-urgent appointment with your child's doctor if:

• Your newborn has scrotal swelling that was not documented at birth
• You notice the scrotum appears larger than normal during diaper changes
• The swelling seems to change size throughout the day (suggesting communicating hydrocele)
• A known hydrocele has been present for more than 12-18 months without improvement
• You have concerns or questions about your child's scrotal appearance

How Is Hydrocele Diagnosed in Children?

Hydrocele is diagnosed through physical examination using a technique called transillumination, where the doctor shines a light through the scrotum. If it's a hydrocele, the light will pass through the clear fluid, making the scrotum glow. An ultrasound may be performed if the diagnosis is uncertain or to rule out other conditions.

The diagnosis of hydrocele in children is usually straightforward and can be made through a careful physical examination in the doctor's office. No blood tests are required, and imaging studies are typically only needed in certain situations where the diagnosis is unclear or additional conditions need to be ruled out.

During the physical examination, the doctor will carefully inspect and palpate (feel) the scrotum. They will assess the size, shape, and consistency of the swelling, and note whether it affects one testicle or both. The testicle itself is examined to ensure it is normal in size and position within the fluid collection. The doctor will also check the inguinal (groin) region for any signs of inguinal hernia, which can coexist with hydrocele.

Transillumination Test

The key diagnostic technique for hydrocele is called transillumination. This simple, painless test involves holding a small light source (such as a penlight or fiber optic light) against the swollen scrotum in a darkened room. If the swelling is caused by a hydrocele (clear fluid), the light will pass through the fluid and cause the scrotum to glow with a characteristic red or pink color – similar to shining a light through your fingers.

Transillumination is highly effective for diagnosing hydrocele because the clear fluid readily transmits light. In contrast, solid masses (such as tumors) or blood collections (hematoceles) will not transmit light and will appear dark. This simple test allows the doctor to quickly differentiate a hydrocele from other causes of scrotal swelling without any discomfort to the child.

When Ultrasound May Be Needed

While transillumination is usually sufficient for diagnosis, scrotal ultrasound may be recommended in certain situations:

• The physical examination findings are unclear or inconclusive
• The testicle cannot be adequately felt through the fluid
• There is concern about an associated inguinal hernia
• The swelling is bilateral and other conditions need to be excluded
• The child has had previous scrotal surgery or trauma
• To differentiate from rare conditions such as testicular tumors

Scrotal ultrasound is a painless, non-invasive imaging test that uses sound waves to create detailed pictures of the scrotum's contents. It can clearly show the fluid collection, confirm that the testicle is normal, and identify any associated conditions such as inguinal hernia or epididymal cysts.

How Is Hydrocele Treated in Children?

Most hydroceles in infants require no treatment as they resolve spontaneously within 12-24 months. Treatment (surgery) is only considered if the hydrocele persists beyond age 2-3 years, is associated with an inguinal hernia, or causes significant symptoms. The surgical procedure, called hydrocelectomy, is safe and highly effective with a success rate exceeding 95%.

The approach to treating hydrocele in children follows a conservative "watchful waiting" strategy in most cases. Because the vast majority of congenital hydroceles resolve on their own, immediate intervention is rarely necessary. This approach differs significantly from how hydroceles are managed in adults, where surgical treatment is more commonly recommended.

During the observation period, your child's doctor will monitor the hydrocele through periodic examinations, typically at routine well-child visits. Parents play an important role in this process by noting any changes in the size of the swelling or any new symptoms. Most pediatricians recommend giving hydroceles at least 12-24 months to resolve before considering surgical intervention, unless there are specific indications for earlier treatment.

Observation and Monitoring

Observation is the first-line approach for uncomplicated hydroceles in infants and young children. During this period:

• No medication or treatment is required
• Your child can participate in all normal activities without restriction
• Regular follow-up appointments allow the doctor to track the hydrocele's progression
• Parents should note any changes in size or the development of new symptoms
• The hydrocele typically shrinks gradually as fluid is reabsorbed

Surgical Treatment: Hydrocelectomy

Surgery becomes the recommended treatment in specific circumstances. The most common indication is persistence of the hydrocele beyond 2-3 years of age, as spontaneous resolution becomes increasingly unlikely after this point. Surgery may also be recommended earlier if the hydrocele is associated with an inguinal hernia (communicating hydrocele with patent processus vaginalis) or if the hydrocele is very large and causing physical discomfort.

The surgical procedure for hydrocele repair is called hydrocelectomy or, in children with a communicating hydrocele, an inguinal approach with ligation of the processus vaginalis. The operation is performed under general anesthesia as an outpatient (day surgery) procedure, meaning your child can go home the same day.

What Happens During Surgery

For a communicating hydrocele (the most common type in children), the surgeon makes a small incision in the inguinal (groin) crease – similar to the approach used for inguinal hernia repair. Through this incision, the surgeon identifies and ties off (ligates) the processus vaginalis, which eliminates the connection between the abdominal cavity and the scrotum. Any existing fluid is drained during the procedure.

For a non-communicating hydrocele, the surgeon may use a scrotal approach, making a small incision in the scrotum to drain the fluid and remove or fold back the excess tissue of the hydrocele sac. Various techniques exist, including the Lord procedure and the Jaboulay procedure, with the choice depending on the specific characteristics of the hydrocele and surgeon preference.

The surgery typically takes 30-45 minutes, and the incisions are closed with dissolvable sutures that do not require removal. Most children wake up quickly from anesthesia and can eat and drink shortly after the procedure.

What Causes Hydrocele in Children?

Hydrocele in children is caused by the incomplete closure of the processus vaginalis, a membrane channel through which the testicles descend before birth. When this channel fails to close properly, fluid from the abdominal cavity can accumulate around the testicle. This is a developmental variation, not caused by anything the parents did or didn't do during pregnancy.

Understanding how hydroceles develop requires some knowledge of male fetal development. During pregnancy, the male testicles initially form inside the abdomen, near the kidneys. As the fetus develops, the testicles gradually migrate downward through a structure called the inguinal canal and into the scrotum. This descent typically occurs during the third trimester of pregnancy, usually between weeks 28 and 36.

As the testicles descend, they are accompanied by a thin membrane extension of the peritoneum (the lining of the abdominal cavity) called the processus vaginalis. This membrane creates a channel that allows the testicles to reach their final position in the scrotum. Under normal circumstances, this channel closes before birth or shortly after, leaving behind only a thin membrane (tunica vaginalis) that surrounds each testicle.

A hydrocele forms when the processus vaginalis does not close completely. If the channel remains fully open, peritoneal fluid can flow freely between the abdomen and the scrotum, creating a communicating hydrocele. If the channel partially closes but some fluid becomes trapped, or if the closure is delayed and fluid accumulates before complete closure, a non-communicating hydrocele results.

Risk Factors

Several factors may increase the likelihood of a child developing a hydrocele:

• Premature birth: The processus vaginalis typically closes during the final weeks of pregnancy, so premature infants have higher rates of hydrocele
• Low birth weight: Associated with overall developmental prematurity
• Family history: Some evidence suggests a genetic component, with hydroceles sometimes running in families
• Male sex: Hydroceles only occur in males due to the anatomical differences in development

It's important for parents to understand that hydrocele is not caused by anything they did or didn't do during pregnancy. It is not related to the mother's diet, activities, or prenatal care. Hydrocele is simply a variation in normal development that occurs in some male infants, and it does not indicate any broader health problem or developmental issue.

What Are the Potential Complications?

Hydrocele itself is a benign condition with no long-term health consequences. It does not affect testicular development, fertility, or future health. The main concern is the possibility of an associated inguinal hernia in communicating hydroceles, which may require surgical repair regardless of the hydrocele status.

One of the most reassuring aspects of hydrocele in children is that it is a truly benign condition with an excellent prognosis. The fluid collection around the testicle does not damage the testicle, does not interfere with normal testicular development, and does not affect future fertility. Even large hydroceles that persist for extended periods do not cause permanent harm to the underlying testicular tissue.

However, there are some related concerns that parents and healthcare providers should be aware of:

Associated Inguinal Hernia

The most significant concern with communicating hydroceles is the potential for an associated inguinal hernia. Because the same open processus vaginalis that allows fluid to accumulate can also allow bowel or other abdominal contents to protrude into the scrotum, children with communicating hydroceles have a higher risk of developing inguinal hernias. Signs that may suggest an associated hernia include:

• A bulge in the groin area that becomes more prominent when crying or straining
• The swelling extends upward into the inguinal region
• The mass feels firmer or more irregular than typical hydrocele fluid

If an inguinal hernia is present, surgical repair is typically recommended to prevent the rare but serious complication of incarceration (bowel becoming trapped).

Psychological Considerations

While hydrocele has no physical complications, some older children may become self-conscious about scrotal swelling if it persists beyond infancy. If your child expresses concerns about appearance or if the hydrocele is causing psychological distress, this may be considered when discussing treatment timing with your healthcare provider.

Frequently Asked Questions About Hydrocele in Children