Hydrocele: A Complete Patient‑Friendly Guide

Overview

A hydrocele is a fluid‑filled sac surrounding a testicle that causes swelling of the scrotum. The fluid is usually clear, resembling a thin wisp of water, and the condition is typically painless. Hydroceles are among the most common causes of scrotal enlargement in infants and in adult men.

• Who it affects: Most often seen in newborn males (congenital hydrocele) and men ages 20‑40. Rarely, women can develop a hydrocele‑like cyst in the labial or para‑vaginal tissue, but the term is almost exclusively used for males.
• Prevalence: In the United States, hydroceles account for approximately 1‑3% of all pediatric surgical consultations, and about 0.5‑2% of adult urology visits. Worldwide, incidence is similar, though exact numbers vary by region due to differences in reporting and access to care.¹

Symptoms

Hydroceles can be asymptomatic, but many men notice the following signs:

• Scrotal swelling: A smooth, painless enlargement that may be larger on one side.
• Feeling of heaviness or pressure: The added fluid can make the testicle feel “full.”
• Transillumination: When a light is shone through the scrotum, the fluid-filled sac glows, a classic clinical clue.
• Changing size: The swelling often fluctuates throughout the day; it may be larger after standing or physical activity and smaller when lying down.
• Pain or discomfort: Usually mild, but may increase if the hydrocele becomes large, becomes infected, or is associated with an underlying condition (e.g., hernia).
• Associated symptoms: Rarely, men experience lower abdomen or groin pain, especially if a concurrent inguinal hernia is present.

Causes and Risk Factors

Primary (Congenital) Hydrocele

During fetal development, the testicle descends from the abdomen into the scrotum through a canal called the processus vaginalis. Normally this canal closes after descent. If it remains partially open, fluid from the abdominal cavity can accumulate around the testicle, forming a hydrocele.

Acquired Hydrocele

• Infection or inflammation: Epididymitis, orchitis, or scrotal cellulitis can increase fluid production.
• Trauma: Direct injury to the scrotum may cause leakage of serous fluid.
• Tumors: Testicular cancer or paratesticular tumors can obstruct lymphatic drainage, leading to fluid buildup.
• Systemic diseases: Heart failure, kidney disease, or liver cirrhosis can cause generalized fluid retention that may involve the scrotum.
• Prior surgery: Hernia repair or scrotal surgery can disrupt normal fluid pathways.

Risk Factors

• Male sex (by definition)
• Infancy (congenital)
• Age 20‑40 (peak for acquired hydrocele)
• History of inguinal hernia or hernia repair
• Recent scrotal infection or trauma
• Chronic medical conditions that cause fluid overload (e.g., congestive heart failure)

Diagnosis

Accurate diagnosis requires a combination of history, physical examination, and occasionally imaging.

Physical Exam

• Inspection: Observe size, symmetry, and translucency.
• Palpation: The hydrocele feels soft and compressible; the testis can usually be felt separately, which helps distinguish it from a solid mass.
• Transillumination test: A small flashlight placed against the scrotal skin will highlight a clear fluid collection (positive) versus a solid tumor (negative).

Imaging Studies

• Scrotal ultrasound: First‑line imaging; distinguishes fluid from solid masses, assesses testicular blood flow, and detects co‑existing hernias. Sensitivity >95% for identifying hydroceles.²
• CT or MRI: Reserved for complex cases or when a tumor is strongly suspected.

Additional Tests (Rare)

• Serum tumor markers (AFP, β‑hCG, LDH) if a testicular cancer is a concern.
• Urinalysis and blood work to evaluate systemic causes of fluid overload.

Treatment Options

Management depends on the patient’s age, hydrocele size, symptom burden, and underlying cause.

Watchful Waiting

In infants, many hydroceles resolve spontaneously within the first 12‑18 months. For asymptomatic adults with small hydroceles, observation is reasonable.

Medical Management

• Anti‑inflammatory drugs: NSAIDs (e.g., ibuprofen) can relieve discomfort from an inflamed hydrocele.
• Antibiotics: Indicated only if an infection is present.
• Diuretics: Not routinely used; may help in patients with generalized fluid overload, but do not treat the hydrocele itself.

Surgical Options

When the hydrocele is large, painful, or cosmetically concerning, surgery is the definitive treatment.

1. Hydrocelectomy (open repair): A small incision is made, the sac is opened, fluid drained, and the sac excised or everted. Success rates exceed 95% with low recurrence.³
2. Minimally invasive (keyhole) hydrocelectomy: Uses laparoscopic or scrotoscopic instruments, offering less postoperative pain and quicker recovery.
3. Sclerotherapy: A sclerosing agent (e.g., phenol or tetracycline) is injected into the hydrocele sac to cause fibrosis and collapse of the space. Suitable for patients who are poor surgical candidates; recurrence rates are higher (10‑20%).

Post‑operative Care

• Scrotal support (tight underwear or jockstrap) for 1‑2 weeks.
• Ice packs to reduce swelling.
• Avoid heavy lifting or vigorous exercise for 2‑4 weeks.
• Analgesics as needed, usually acetaminophen or NSAIDs.

Living with Hydrocele

Even after successful treatment, some men experience lingering concerns. Below are practical tips for daily management.

• Self‑examination: Perform a monthly check to note any new swelling, firmness, or change in size. Early detection of recurrence or tumor improves outcomes.
• Clothing: Wear supportive, breathable underwear to minimize discomfort.
• Hydration & diet: Adequate fluid intake helps overall fluid balance; a low‑salt diet may be beneficial for those with heart or kidney disease.
• Activity: Light to moderate exercise is safe; avoid activities that cause prolonged standing or heavy lifting if you have a large hydrocele.
• Follow‑up appointments: After surgery, a scrotal ultrasound at 3‑6 months confirms resolution.

Prevention

Because many hydroceles are congenital, primary prevention is limited. However, reducing modifiable risk factors can lower the chance of acquiring an adult hydrocele.

• Promptly treat scrotal infections and epididymitis.
• Wear protective gear during sports to prevent traumatic injury.
• Manage chronic diseases (heart failure, kidney disease, cirrhosis) with your physician to avoid generalized fluid overload.
• Perform regular testicular self‑exams to catch early abnormalities.

Complications

While most hydroceles are benign, complications can arise if left untreated.

• Hydrocele rupture: Very rare; sudden release of fluid can cause acute pain.
• Infection (hydrocele abscess): Presents with redness, warmth, fever, and severe pain; requires antibiotics and possibly drainage.
• Infertility: Very large hydroceles may increase scrotal temperature, potentially impairing sperm production.
• Associated inguinal hernia: About 10‑20% of adult hydroceles coexist with a hernia; missing the hernia can lead to incarceration.
• Testicular cancer: A hydrocele masks a tumor, delaying diagnosis. Regular exams are essential.

When to Seek Emergency Care

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**Sources**

1. Huang Y et al. “Hydrocele: Epidemiology and Management.” Urology Journal. 2017;12(4):215‑223. PMCID: PMC5293825
2. Mayo Clinic. “Scrotal ultrasound.” Accessed July 2026. Mayo Clinic
3. Cleveland Clinic. “Hydroceles.” 2024. Cleveland Clinic
4. CDC. “Testicular Cancer Prevention and Early Detection.” 2023. CDC
5. NIH National Institute of Diabetes and Digestive and Kidney Diseases. “Hydrocele.” 2022. NIH