Hydrocele in Adults: Symptoms, Causes, and Treatment in the UK

A hydrocele is a type of swelling in the scrotum that occurs when fluid collects in the thin sheath surrounding a testicle. While very common in newborns, it can also develop in adult men due to inflammation or injury. In the UK, it is one of the most frequent causes of scrotal enlargement seen by GPs.

Unlike many other conditions affecting the male reproductive system, a hydrocele is typically painless. It may feel like a small balloon filled with water inside the scrotum. It can affect one side (unilateral) or both sides (bilateral). Although generally harmless and not a threat to fertility, the sheer size of the swelling can cause discomfort or lead to embarrassment, prompting men to seek medical advice.

The primary symptom of a hydrocele is a painless swelling of one or both testicles. For many British men, the first sign is simply noticing that the scrotum looks larger than usual or feels heavier. Key characteristics include:

• Consistency: The swelling often feels smooth and soft, though if the fluid is under high pressure, it may feel quite firm.
• Fluctuation in size: Some hydroceles stay the same size, while others may get larger during the day and smaller at night while lying down.
• Lack of pain: Pain is rare unless there is an underlying infection (epididymitis) or the swelling is so large it causes a dragging sensation in the groin.

If you notice any redness, sudden sharp pain, or if the lump is separate from the testicle and feels hard, it is essential to consult a GP or an online doctor promptly, as these can indicate different urological issues.

In adult men, hydroceles are usually 'acquired' rather than congenital. The fluid is produced and absorbed constantly in the scrotal lining; a hydrocele develops when this balance is disrupted. Common causes include:

• Minor Injury: A knock or trauma to the scrotum can trigger fluid accumulation.
• Inflammation: Infections such as epididymitis (inflammation of the tube at the back of the testicle) or orchitis (inflammation of the testicle itself) can lead to secondary hydroceles.
• Post-Surgical Complications: Sometimes, surgery for an inguinal hernia or a varicocele can result in a hydrocele.

NICE guidance suggests that while most are idiopathic (no known cause), doctors must always check that the swelling isn't a reaction to a more serious underlying pathology, such as a testicular tumour, which is why a professional diagnosis is non-negotiable.

Physical Examination

Your GP will first examine the scrotum. A classic technique used is transillumination. The doctor shines a bright light through the scrotum; if it is a hydrocele, the light will show a clear fluid-filled space. If the light does not pass through, it may suggest a solid mass or a hernia.

Ultrasound Scanning

According to NHS protocols, if there is any doubt about the diagnosis or if the doctor cannot feel the testicle clearly through the fluid, an ultrasound scan is requested. This is a painless procedure that uses sound waves to create a clear image of the internal structures, confirming the presence of fluid and ensuring the testicle itself appears healthy.

Differentiating from a Hernia

It is important to distinguish a hydrocele from an inguinal hernia. A hernia occurs when part of the bowel pokes through a weak spot in the abdominal wall into the scrotum. Unlike a hydrocele, a hernia can often be 'pushed back' into the abdomen and may get larger when you cough (cough impulse).

If a hydrocele is small and not causing physical discomfort or psychological distress, the standard UK clinical approach is 'watchful waiting'. Many hydroceles in adults resolve on their own over several months, especially if they were caused by a self-limiting infection.

Hydrocelectomy

If the swelling is large, uncomfortable, or unsightly, surgery may be recommended. This procedure, known as a hydrocelectomy, involves making a small incision in the scrotum or groin to drain the fluid and remove the sac. This is usually performed as a day-case procedure under general or spinal anaesthetic.

Aspiration

Fluid can be removed using a needle (aspiration), but this is rarely recommended in the UK because the fluid almost always returns within a few weeks. It is generally reserved for men who are not fit enough for surgery.

Many men find it difficult or embarrassing to discuss scrotal changes. Using an online doctor in the UK can offer a discreet, professional environment to discuss your concerns. While an online GP cannot perform a physical examination or transillumination, they are excellently placed to:

• Evaluate your symptoms and medical history.
• Provide a clinical opinion on the likelihood of a hydrocele.
• Explain the diagnostic pathway and what to expect from an ultrasound.
• Issue referral letters for private urological consultations or imaging.
• Advise on whether your symptoms require urgent 'Red Flag' attention.

Seeking advice early ensures peace of mind and prevents the unnecessary anxiety often associated with self-diagnosis.