Hydrocele

What is hydrocele?

A hydrocele is a collection of fluid that builds up around a testicle, causing the scrotum (the pouch of skin that holds the testicles) to swell. The fluid gathers inside a thin sac called the tunica vaginalis, which normally surrounds each testicle with only a very small amount of lubricating fluid. When too much fluid collects in this sac, the scrotum becomes enlarged on one or both sides. In medical coding systems, this condition is listed under ICD-10 code N43.3, which refers to a hydrocele that is not otherwise specified.

Hydroceles are common in newborn boys. During development before birth, the testicles move down from the abdomen into the scrotum through a passage. A small amount of fluid can travel down with them, and in many infants this fluid is absorbed naturally during the first year of life. In adults, a hydrocele can develop at any age, though it is seen more often in men over 40. Adult hydroceles may appear gradually without a clear cause, or they may follow an injury, infection, or inflammation in the scrotum.

For many people asking “what is hydrocele” after noticing scrotal swelling, the most reassuring point is this: a hydrocele itself is usually painless and, in most cases, is not dangerous. It does not typically affect fertility or the testicle itself. However, because other conditions—some of them serious—can also cause scrotal swelling, any new swelling should always be checked by a doctor rather than assumed to be a hydrocele.

Symptoms of hydrocele

The main sign of a hydrocele is painless swelling of one or both sides of the scrotum. The swelling often feels like a small, fluid-filled balloon and is usually smooth to the touch. Common hydrocele symptoms include:

• Visible enlargement of one or both sides of the scrotum
• A feeling of heaviness or fullness in the scrotum, especially as the swelling grows
• Swelling that changes size during the day in some cases, often smaller in the morning and larger by evening
• Little or no pain in most uncomplicated hydroceles
• Discomfort when walking or sitting if the hydrocele becomes large

Symptoms can differ depending on the type of hydrocele. Doctors often describe two main types:

• Non-communicating hydrocele: the sac around the testicle is closed, and the fluid stays trapped inside. The swelling tends to remain fairly constant in size or changes only slowly over time. This is the more common type in adults.
• Communicating hydrocele: a small opening remains between the abdomen and the scrotum, allowing fluid to flow back and forth. The swelling may appear smaller after lying down overnight and larger after standing or activity during the day. This type is more common in infants and is closely related to an inguinal hernia (a condition in which abdominal tissue pushes through a weak spot in the groin).

In babies, parents may notice that one side of the scrotum looks larger, especially when the baby cries or strains. In adults, a hydrocele may go unnoticed for a long time if it is small. Larger hydroceles can cause a dragging sensation, interfere with clothing or physical activity, and cause embarrassment or anxiety, even when they are not painful.

Pain is not a typical feature of a simple hydrocele. If scrotal swelling is painful, tender, red, or came on suddenly, this suggests a different or additional problem—such as infection, injury, or testicular torsion (a twisting of the testicle that cuts off its blood supply)—and needs prompt medical attention.

Causes and risk factors

Hydrocele causes differ between infants and adults.

In babies

Before birth, each testicle develops inside the abdomen and then descends into the scrotum through a canal, bringing a sleeve of the abdominal lining with it. Normally this sleeve closes on its own. If it stays open, or if fluid remains trapped after it closes, a hydrocele forms. Premature babies have a higher chance of being born with a hydrocele because there is less time for this passage to close before birth.

In older children and adults

In many adults, a hydrocele develops slowly without any identifiable cause. This is sometimes called an idiopathic hydrocele, meaning the cause is unknown. When a cause can be identified, it may include:

• Injury to the scrotum, including sports injuries or accidents
• Infection or inflammation, such as epididymitis (inflammation of the tube behind the testicle) or orchitis (inflammation of the testicle itself)
• Previous surgery in the groin or scrotal area, after which fluid can sometimes accumulate
• Filariasis, a parasitic infection spread by mosquitoes that is a common cause of large hydroceles in some tropical regions
• Rarely, a tumor of the testicle, which can be accompanied by fluid around the testicle; this is one reason doctors examine any scrotal swelling carefully

Risk factors

Factors that may increase the likelihood of developing a hydrocele include being born prematurely, older age in adults, a history of scrotal injury or infection, and living in or traveling to regions where filariasis occurs. That said, many hydroceles occur in people with none of these risk factors.

Diagnosis of hydrocele

Hydrocele diagnosis usually begins with a physical examination. The doctor will gently examine the scrotum to assess the size, location, and feel of the swelling, and to check whether the testicle can be felt separately from the fluid. The doctor may also check for tenderness and may examine the abdomen and groin to look for a hernia.

Common steps in confirming the diagnosis include:

• Transillumination: the doctor shines a light through the scrotum in a darkened room. Because a hydrocele is filled with clear fluid, the light typically glows through it. Solid masses do not transmit light in the same way. This simple test can support the diagnosis, but it is not enough on its own to rule out other conditions.
• Scrotal ultrasound: this is the key imaging test. Ultrasound uses sound waves to create a picture of the scrotum and its contents. It confirms that the swelling is fluid, shows the condition of the testicle behind the fluid, and helps exclude other causes of swelling such as a hernia, a tumor, or a collection of blood. It is painless and does not use radiation.
• Urine and blood tests: if the doctor suspects an infection is contributing to the swelling, tests may be ordered to look for signs of infection or inflammation.

In infants and children, the doctor may also observe whether the swelling changes with position or with crying, which can suggest a communicating hydrocele. If a hernia is suspected alongside the hydrocele, this influences the treatment plan, because hernias generally require repair while many infant hydroceles do not.

An important goal of diagnosis is to make sure the swelling is truly a hydrocele and not something else. Conditions that can look or feel similar include inguinal hernia, epididymal cysts (fluid-filled sacs near the testicle), varicocele (enlarged veins in the scrotum), and, rarely, testicular cancer. This is why self-diagnosis is not appropriate and a professional evaluation—usually including ultrasound—is recommended for any new scrotal swelling.

Treatment options for hydrocele

Hydrocele treatment depends on the patient’s age, the size of the hydrocele, the symptoms it causes, and whether there is an associated hernia or other underlying condition. At hospital groups such as Acibadem, hydroceles are typically managed by the urology department, and pediatric cases by pediatric surgery or pediatric urology specialists.

Watchful waiting

In newborns and infants, most hydroceles resolve on their own as the body absorbs the fluid, often within the first 12 months of life. For this reason, doctors usually recommend simple observation during this period, with regular check-ups to monitor the swelling. If the hydrocele persists beyond roughly one to two years of age, or if it grows or is associated with a hernia, surgical repair is generally considered.

In adults, small hydroceles that cause no discomfort often do not need any treatment. Some resolve on their own, particularly those that follow an infection or minor injury, once the underlying cause settles. Your doctor may suggest monitoring the hydrocele over time rather than intervening straight away.

Medication

There is no medication that shrinks or cures a hydrocele itself. However, if the hydrocele is related to an infection such as epididymitis, the doctor may prescribe antibiotics to treat the infection, and the fluid may then decrease as the inflammation resolves. Pain relievers may be suggested for discomfort in the short term, but they do not treat the fluid collection.

Aspiration (needle drainage)

Aspiration means draining the fluid with a needle. While this can temporarily reduce the swelling, the fluid frequently returns because the sac that produced it remains in place. Aspiration also carries a risk of infection. For these reasons, it is generally not the preferred long-term treatment, although it may be considered in selected patients who cannot safely undergo surgery. Sometimes aspiration is combined with sclerotherapy, in which a medication is injected into the sac to encourage it to close; this may reduce the chance of the fluid coming back, but recurrence is still possible.

Surgery (hydrocelectomy)

Surgical removal of the hydrocele, called hydrocelectomy, is the standard definitive treatment when a hydrocele is large, uncomfortable, growing, or persistent. The operation is usually performed under general or regional anesthesia. In adults, the surgeon typically makes a small incision in the scrotum, drains the fluid, and removes or repositions part of the sac so that fluid cannot re-accumulate. In children with a communicating hydrocele, the surgeon usually operates through a small incision in the groin and closes the open passage between the abdomen and the scrotum, which also addresses any associated hernia.

Hydrocelectomy is generally considered a routine procedure, and many patients go home the same day or after a short stay. As with any operation, there are potential risks, including bleeding, infection, swelling, blood clot formation in the scrotum (hematoma), injury to nearby structures, and recurrence of the hydrocele. Your surgeon can discuss how these risks apply in your individual situation.

Recovery after surgery

After hydrocele surgery, some swelling and bruising of the scrotum is normal and may take several weeks to settle fully. Doctors often recommend rest, supportive underwear, and avoiding heavy lifting and strenuous activity for a period defined by the surgical team. Most people can return to light daily activities within days, but full recovery timelines vary from person to person, so it is important to follow the specific instructions given after the operation.

Living with hydrocele and outlook

For most people, the outlook with a hydrocele is good. A simple hydrocele does not usually harm the testicle, does not typically affect fertility, and is not a form of cancer. Many infant hydroceles disappear without any treatment, and many small adult hydroceles remain stable and cause no problems.

Living with an untreated hydrocele is often manageable if it is small. Supportive underwear can ease a feeling of heaviness, and routine follow-up allows your doctor to confirm that the swelling is not changing in a concerning way. If a hydrocele grows large, it can interfere with walking, sitting, physical activity, or intimacy, and at that point treatment is usually worth discussing.

After surgical repair, most hydroceles do not come back, although recurrence is possible in a minority of cases. No treatment can be guaranteed to be permanent, and outcomes vary between individuals. If swelling returns after treatment, it should be evaluated again rather than assumed to be the same problem.

It is also worth remembering that a hydrocele can occasionally accompany another condition, such as an infection, hernia, or, rarely, a testicular tumor. Attending follow-up appointments and reporting any new symptoms—such as pain, rapid change in size, or a firm lump—helps ensure that nothing else is missed.

Frequently asked questions

What is hydrocele in simple terms?

A hydrocele is a buildup of fluid in the thin sac that surrounds a testicle, which makes the scrotum swell. It is common in newborn boys and can also develop in adult men. In most cases it is painless and not dangerous, but any scrotal swelling should be examined by a doctor to confirm the diagnosis and rule out other causes.

Can a hydrocele heal on its own?

Often, yes—especially in babies. Many infant hydroceles are absorbed naturally within the first year of life without treatment. In adults, small hydroceles sometimes resolve on their own, particularly when they follow an infection or minor injury. However, hydroceles that persist, grow, or cause discomfort usually do not disappear without treatment, and your doctor may recommend surgery in those cases.

How serious is a hydrocele?

A simple hydrocele is generally not serious. It is not cancer, and it does not usually damage the testicle or affect fertility. The main concerns are discomfort from a large hydrocele and the possibility that the swelling is caused by something else, such as a hernia, infection, or, rarely, a tumor. This is why medical evaluation, usually including an ultrasound, is important for any new scrotal swelling.

What are the most common hydrocele symptoms?

The most common symptom is painless swelling of one or both sides of the scrotum, sometimes accompanied by a feeling of heaviness or fullness. The swelling may vary in size during the day, particularly in communicating hydroceles. Pain, redness, tenderness, or sudden severe swelling are not typical hydrocele symptoms and suggest a different problem that needs prompt attention.

Does hydrocele treatment always require surgery?

No. Many hydroceles—especially in infants and in adults with small, symptom-free swellings—are simply monitored over time. Surgery, called hydrocelectomy, is usually reserved for hydroceles that are large, uncomfortable, growing, or persistent, or for children whose hydrocele has not resolved by about one to two years of age. Needle drainage is another option in selected cases, but the fluid often returns, so it is not usually the preferred long-term solution.

How long is recovery after hydrocele surgery?

Recovery varies from person to person. Many patients go home the same day and return to light activities within a few days, while swelling and bruising in the scrotum can take several weeks to settle completely. Doctors typically advise avoiding heavy lifting and strenuous exercise for a period after surgery. Your surgical team will give you a recovery plan tailored to your situation, and it is important to follow their specific instructions.

Can a hydrocele affect fertility?

A simple hydrocele does not usually affect fertility, because the fluid sits around the testicle rather than inside it. In some cases, however, a hydrocele occurs alongside another condition—such as an infection or inflammation—that could affect the testicle. If you have concerns about fertility, it is reasonable to raise them with your doctor during evaluation of the hydrocele.

When to see a doctor

Any new or unexplained swelling of the scrotum should be evaluated by a doctor, even if it is painless, so that the cause can be confirmed. In infants, mention any scrotal swelling to the pediatrician at the next visit, or sooner if it changes suddenly. Adults with persistent or enlarging scrotal swelling should arrange an evaluation with a urologist; at Acibadem, this condition is managed within the urology and pediatric surgery departments.

Seek urgent medical care if any of the following red-flag signs occur, as they may indicate a condition that needs immediate treatment:

• Sudden, severe scrotal pain, which can be a sign of testicular torsion—a medical emergency in which the testicle’s blood supply is cut off
• Scrotal swelling with fever, redness, or warmth of the skin, which may indicate infection
• Swelling after an injury to the scrotum or groin
• Nausea or vomiting together with scrotal or groin pain
• A hard lump on the testicle, or swelling that feels solid rather than fluid-filled
• In a baby, swelling that suddenly becomes hard, tender, or discolored, or that is accompanied by vomiting or inconsolable crying, which may suggest a trapped (incarcerated) hernia
• Rapid growth of the swelling over days rather than months

Prompt evaluation of these warning signs allows serious conditions to be treated early. For an uncomplicated hydrocele, timely diagnosis provides reassurance and helps you and your doctor decide together whether observation or treatment is the right approach for you.