Renal & Urology

Hydrocoele

A hydrocoele is a fluid collection around the testis; uncomplicated infantile hydrocoeles often resolve, while new, atypical or adult swellings require confident testicular assessment and surgery only when symptoms or cause justify it.

In a nutshell

Hydrocoele is fluid around the testis. In infants, an uncomplicated hydrocoele often resolves and can be observed; persistent, large or hernia-associated swellings need paediatric surgical review. In adults, assess the testis clinically or by ultrasound when it cannot be felt, observe if minimally symptomatic, and refer for definitive repair when symptoms are significant. Sudden pain is an emergency.

Classic presentation

A painless, fluctuant scrotal swelling that transilluminates and surrounds the testis; in an infant it may vary in size, while in an adult the testis may be difficult to palpate.

Key points

A hydrocoele surrounds the testis; an epididymal cyst is separate from it.
An uncomplicated infantile hydrocoele can be observed because many resolve in the first years of life.
A large or adult hydrocoele must not obscure an unexamined testis; use ultrasound when the testis cannot be assessed confidently.
Sudden severe pain, nausea/vomiting or a high-riding testis requires emergency torsion assessment.
Symptomatic adult hydrocoeles are usually referred for specialist repair; aspiration alone commonly recurs.

First-line investigation

Focused examination; ultrasound when the testis is impalpable, the presentation is new/atypical or the diagnosis is uncertain.

Management

Exclude emergencies

Acute severe pain or an irreducible groin/scrotal swelling requires emergency assessment for torsion or hernia.^6,7

Assess the testis and cause

Use examination first; arrange ultrasound if the testis cannot be felt or the hydrocoele is new, atypical, persistent or diagnostically uncertain.^4,1,2

Observe or refer

Observe uncomplicated infantile hydrocoele and minimally symptomatic confirmed adult disease; refer persistent/large/hernia-associated childhood disease or symptomatic adult disease.^2,5,3

Exam traps

A hydrocoele can transilluminate, but transillumination does not exclude a secondary cause.
Do not apply one rigid age threshold to every infantile hydrocoele; local paediatric pathways and hernia risk matter.
Do not reassure an adult with a large new hydrocoele without accounting for the testis.
Aspiration alone is prone to recurrence and is not the routine definitive cure.

Illustrations

Sensitive clinical image, hidden — Transillumination of a hydrocoeleA clinical photograph of a scrotal hydrocoele glowing red when transilluminated with a torch in a darkened room.Mikael Häggström, M.D. Author info, Wikimedia Commons · CC0

Key sources

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.