Hydrocele

A hydrocoele is a build-up of fluid in a sac around your testicle, causing your scrotum to swell. It's usually painless and often needs no treatment, although surgery may be recommended if it becomes large or uncomfortable.

Symptoms of a hydrocoele

The main sign of a hydrocoele is swelling on one or both sides of your scrotum that feels like a water-filled balloon. It's usually smooth and sits mainly in front of your testicle. Other things you might notice include:

• swelling that changes in size during the day
• a heavy feeling in your scrotum
• swelling that gets bigger after activity
• discomfort when walking, sitting or during sexual activity if the hydrocoele is large

Hydrocoeles are usually painless. Very large hydrocoeles, which sometimes develop gradually over several years, are more likely to cause discomfort simply because of their size.

Causes of hydrocoele and who is at risk

In babies, a hydrocoele usually forms during development in the womb. Fluid can flow from the abdomen into the scrotum through a passage that hasn't sealed properly, or fluid can remain in the scrotum even after this passage closes. Around 1 in 10 newborn boys has a hydrocoele, and it usually clears up on its own within the first year or two.

In older boys, teenagers and adults, hydrocoeles are less common, affecting only around 1% of adult men, and are usually caused by an injury or inflammation of the scrotum. Most hydrocoeles in adults are most common in men over 40, and in many cases there's no obvious cause.

A hydrocoele can sometimes be linked to:

• an infection, inflammation or injury affecting your testicle
• a tumour affecting your testicle
• surgery for a varicocele (swollen veins in the scrotum)
• generalised fluid retention affecting the lower half of your body
• an inguinal hernia, where abdominal tissue pushes into the groin.

Are there different types of hydrocoele?

There are two main types of hydrocoele:

• a communicating hydrocoele, where a passage remains open between your abdomen and scrotum, allowing fluid to flow between them, so the swelling can change size during the day
• a noncommunicating (or simple) hydrocoele, where this passage has closed, but fluid still builds up around the testicle, usually staying a similar size.

How a hydrocoele is diagnosed

A doctor will usually examine your scrotum and testicles, and may apply gentle pressure or ask you to cough to see how the swelling changes. They may also shine a light through your scrotum (transillumination), which helps confirm that the swelling is fluid rather than a solid lump.

If the hydrocoele is large enough that your testicle can't be felt clearly, the fluid may be drained with a needle and syringe, using local anaesthetic to make this painless, so the testicle can be examined properly. Your doctor may also request an ultrasound scan to check your testicle and rule out an underlying cause.

How a hydrocoele is treated

If a hydrocoele isn't causing symptoms, one option is simply to leave it alone. Many hydrocoeles, especially in infants, go away on their own without any treatment, and there are no medications that can shrink one.

The fluid can be drained with a needle and syringe, but it commonly refills within a few months, so this is usually only a short-term option. A solution called a sclerosant can sometimes be injected after draining to help stop the fluid coming back, although this isn't commonly used and is mainly offered to people who aren't suitable for surgery.

Surgery, known as hydrocoelectomy, is recommended if a hydrocoele is large, uncomfortable, or doesn't go away on its own. It's usually a day case procedure carried out under general or local anaesthetic.

• in children, a small cut is made near the groin to repair the open passage to the abdomen and drain the fluid
• in adults, a small cut is made in the scrotum or lower abdomen, the fluid is drained, and the sac is closed or removed so it cannot refill.

Stitches usually dissolve on their own within 2 to 3 weeks. Risks of surgery include infection, bruising, swelling, and a small chance that the hydrocoele returns, although the operation has a high success rate overall.

After surgery, you may feel tired for a few days and can take your usual painkillers, such as paracetamol, for discomfort. It's best to avoid heavy lifting and exercise for 10 to 14 days, and to wear close-fitting underwear for support for a few weeks.

When to see a doctor

See a doctor if:

• you notice any new swelling or lump in your scrotum, so it can be properly examined
• a hydrocoele becomes larger, more uncomfortable, or starts to affect your daily activities
• your child seems to be in pain, is vomiting, or isn't eating as much as usual

If you've had surgery, contact your GP immediately if your wound becomes increasingly painful, inflamed, or starts to weep.