Urology • Condition

Hydrocele

Medical term: Hydrocele

A hydrocele is a collection of clear fluid within the thin sac surrounding a testicle. It usually causes smooth, painless swelling on one or both sides of the scrotum.

A new scrotal swelling should always be examined because hernia, infection, trauma, torsion and a testicular mass can look similar or occur alongside a hydrocele.

Seek immediate medical care

Sudden Pain or Rapid Scrotal Swelling?

Do not assume sudden painful swelling is a hydrocele. Obtain emergency assessment for:

  • Sudden severe pain in one testicle or one side of the scrotum.
  • Rapid swelling with nausea, vomiting or lower-abdominal pain.
  • A testicle that appears higher or lies differently from usual.
  • Severe pain or swelling beginning soon after an injury.
  • A painful firm groin or scrotal bulge that cannot be gently reduced.
  • Fever, chills, spreading redness, dark skin, weakness or confusion.

Testicular torsion can interrupt blood flow and needs treatment within hours. A trapped hernia and severe infection can also require urgent surgery. Do not wait for a routine scan.

What is a Hydrocele?

Each testicle is partly surrounded by a thin membrane called the tunica vaginalis. This membrane normally contains a small amount of lubricating fluid. A hydrocele forms when more fluid collects than the body can absorb.

Hydroceles are usually benign and do not become cancer. The important clinical task is confirming that the swelling really is fluid and that the testicle and nearby structures are normal.

Doctor's Insight

Being painless does not make a new scrotal swelling safe to self-diagnose. A large hydrocele can also hide the testicle, making examination or ultrasound especially important.

How Can a Hydrocele Present?

Painless swelling One side or both sides enlarge gradually without acute pain.
Heaviness or dragging A larger collection can feel bulky during walking or exercise.
Changing size A communicating hydrocele may be smaller after lying down and larger later.
Discomfort from size Skin irritation, pressure or difficulty with activity can develop.

Details worth reporting include:

  • When the swelling appeared and whether it is growing.
  • Whether it changes with standing, activity, coughing or lying down.
  • Pain, redness, fever, urinary symptoms or urethral discharge.
  • A firm area, lump or change in the testicle itself.
  • Recent trauma, infection, hernia repair, varicocele surgery or radiotherapy.
  • Travel or residence in an area where lymphatic filariasis occurs.

What Types of Hydrocele Occur?

Infant non-communicating hydrocele Fluid remains around the testicle after the abdominal connection closes. Many resolve as the fluid is naturally absorbed.
Communicating hydrocele An open passage between the abdomen and scrotum allows fluid to move, so size may vary. The same opening can be associated with an inguinal hernia.
Hydrocele of the spermatic cord Fluid is trapped along the cord above the testicle and may feel like a separate groin or upper-scrotal lump.
Adult or acquired hydrocele Fluid production and absorption become unbalanced. It may be idiopathic or occur after inflammation, injury or surgery.
Reactive hydrocele Fluid accompanies another scrotal condition such as infection, inflammation, torsion, trauma or, rarely, a testicular tumour. The underlying condition requires treatment.
Filarial hydrocele Lymphatic filariasis can damage scrotal lymphatic drainage in endemic settings. Evaluation and treatment are cause-specific and may include infection care and hydrocele surgery.

What Else Can Cause Scrotal Swelling?

Inguinal hernia Bowel or abdominal tissue enters the groin or scrotum. It may change with coughing or position and can become trapped.
Epididymitis or epididymo-orchitis Infection or inflammation more often causes tenderness, warmth, urinary symptoms or fever, sometimes with reactive fluid.
Varicocele or epididymal cyst Enlarged veins or a separate fluid-filled cyst have different examination and ultrasound appearances.
Testicular torsion Sudden severe pain and swelling require emergency assessment; torsion cannot be excluded by assuming the fluid is a hydrocele.
Testicular tumour A firm intratesticular area may be painless. Ultrasound is essential when the testicle is difficult to feel or a mass is suspected.

Questions Your Doctor May Ask

Does the swelling change through the day?

A collection that enlarges while standing or active and reduces after lying down may communicate with the abdomen or represent a hernia.

Was there pain, infection, trauma or surgery?

Sudden onset, fever, urinary symptoms, injury, hernia repair or another scrotal procedure may point to an acquired or reactive cause.

Can you feel the testicle separately?

Do not repeatedly squeeze the swelling to find out. Tell the clinician if the testicle feels hidden or if you have noticed a separate firm area.

How does it affect daily life?

Walking, exercise, work, clothing, sleep, sexual activity, skin care and emotional wellbeing all help determine whether treatment is worthwhile.

How is a Hydrocele Diagnosed?

1 History and physical examination

The clinician checks size, tenderness and whether the testicle is palpable, and examines the groin and abdomen for a hernia or connection.

2 Transillumination

Light may pass through clear fluid, supporting the diagnosis. This bedside sign is helpful but cannot safely exclude every hernia, tumour or other scrotal condition.

3 Scrotal ultrasound

Ultrasound confirms fluid, examines the testicle and epididymis, and looks for a mass, hernia, inflammation or another cause. Doppler evaluates blood flow when pain or torsion is a concern.

4 Cause-directed tests

Urine, infection, tumour-marker or filariasis testing is selected only when the history, examination or ultrasound indicates a need.

When is Observation Appropriate?

Most infants Observation is usually appropriate during at least the first year because spontaneous resolution is common. Follow-up confirms that swelling is improving and no hernia or testicular problem appears.
Small comfortable adult hydrocele After the diagnosis and testicle are confirmed, observation is reasonable when size is stable and daily life is unaffected.
Recently acquired hydrocele A collection related to temporary inflammation or injury may reduce while the cause is treated and the scrotum is monitored.

Earlier surgical review is appropriate when a child may have a hernia or underlying testicular condition, or when a hydrocele persists, enlarges substantially or causes symptoms.

How is a Hydrocele Treated?

Treat an underlying condition Infection, trauma, torsion, tumour, hernia or another cause is managed first or alongside treatment of the fluid collection.
Adult hydrocele repair Through a small scrotal incision, fluid is drained and the surrounding sac is folded, turned behind the testicle, repaired or partly removed to reduce re-accumulation. Our Hydrocelectomy guide explains the operation, alternatives, recovery and risks in detail.
Paediatric communicating-hydrocele repair The open passage to the abdomen is closed through an inguinal or selected minimally invasive approach, similar to treating a hernia connection.
Needle aspiration Removing fluid with a needle does not repair the sac, so fluid usually returns quickly. It can introduce infection and is not standard definitive treatment; exceptional use requires specialist discussion.

What Can You Expect After Hydrocele Repair?

Bruising, discomfort and swelling are expected for several days and may take weeks to settle. The operated side can feel bulkier because repaired sac tissue remains around the testicle. Supportive underwear and the surgeon's individual wound, activity and pain-relief instructions help recovery.

Contact the surgical team promptly for:

  • Swelling, bruising or pain that becomes progressively worse.
  • Fever, spreading redness, pus or wound separation.
  • A rapidly enlarging tense scrotum or heavy bleeding.
  • Difficulty passing urine, dizziness or feeling significantly unwell.

Possible complications include haematoma, infection, recurrence, chronic discomfort and uncommon injury to the epididymis, spermatic duct or testicular blood supply. Individual risk should be discussed during consent.

What Should You Avoid?

  • Do not dismiss sudden pain as pressure from a known hydrocele.
  • Do not repeatedly squeeze, massage or try to drain the swelling yourself.
  • Do not rely on a torch test at home to rule out a tumour or hernia.
  • Do not take antibiotics unless infection has been clinically assessed.
  • Do not ignore a new firm area or a testicle that cannot be felt separately.

A Hydrocele Can Hide Another Condition

Fluid itself is usually benign, but it may make examination difficult or arise in response to another scrotal problem. That is why confirming the testicle's appearance is part of a proper assessment.

Myth vs Fact

Myth Every hydrocele needs an operation.
Fact Many infant hydroceles resolve, and a confirmed small adult hydrocele can be observed when it causes no difficulty.
Myth A painless swelling cannot be serious.
Fact Hernia and testicular tumours can be painless. Every new scrotal swelling deserves clinical examination.
Myth Needle drainage permanently cures a hydrocele.
Fact Fluid commonly re-accumulates because aspiration does not repair the sac and may also introduce infection.

Frequently Asked Questions

Can a hydrocele become cancer?

A hydrocele does not normally turn into cancer. However, a tumour can sometimes cause reactive fluid or be difficult to feel behind a large hydrocele, so examination and ultrasound remain important.

Can a hydrocele affect fertility?

An uncomplicated hydrocele usually does not prevent fertility. The underlying testicular condition may matter, and hydrocele surgery has uncommon risks to nearby reproductive structures that are discussed before treatment.

Why does the swelling change size?

A communicating hydrocele allows fluid to move between the abdomen and scrotum, so it may enlarge when upright or active and reduce after lying down. A hernia must also be considered.

Will supportive underwear cure it?

Support may reduce heaviness or movement-related discomfort but does not remove the fluid or close a communicating passage. It is a comfort measure, not definitive treatment.

Can a hydrocele return after surgery?

Recurrence is possible but uncommon after definitive repair. A returning or changing swelling should be re-examined rather than assumed to be the same problem.

A Note From Our Doctors

The information on this page is intended to help you understand your condition. It should not be considered a diagnosis or a substitute for a consultation with a qualified medical professional.

Every patient is unique. The same symptom can have different causes in different individuals, and the most appropriate investigations and treatment depend on your medical history, examination findings, age, existing medical conditions and test results.

At SR Speciality Hospital, we believe in treating the whole patient—not just a symptom, scan or laboratory report. Every treatment plan is individualised after careful medical evaluation.

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