A hydrocele can affect one or both testicles and is common in baby boys – affecting around one in 10. It’s usually a painless swelling but can cause some discomfort.
The swelling is caused by a build-up of fluid in a sac that surrounds the testicle inside the scrotum.
Hydroceles are often associated with inguinal hernias – where part of your bowel, bladder or other abdominal structures push out of your abdomen and into your groin. A hydrocele and/or an inguinal hernia can occur when the channel connecting your testicles to your abdomen is too wide.
Baby boys may have a congenital hydrocele (present at birth) due to the way the testicles and the channel through the abdomen develop in the later stages of pregnancy. A channel that’s too narrow or closed can trap fluid inside the sac around the testicle, whereas a channel that’s too wide can allow fluid to drain from the abdomen and collect in the sac.
A congenital hernia will usually go away on its own within the first year after birth. However, it’s still important to get it checked by a doctor, as testicular swelling is also associated with other conditions.
Older boys and men
In older males, hydrocele causes include:
A small hydrocele may not need treatment, but for larger or uncomfortable swellings, surgery is the best way to ensure it doesn’t return.
The swollen scrotum will feel like a filled water balloon. Often, there are no other symptoms other than the painless swelling. A hydrocele may become painful or tender if the swelling is very large.
Your doctor will examine your scrotum and also check for an inguinal hernia. They’ll shine a light through your scrotum – the outline of the testicle will show up as light passes through the fluid surrounding it.
They may also recommend blood or urine tests to check for infection or an ultrasound scan to rule out a hernia, testicular cancer or other causes.
Most hydroceles in young babies go away on their own and don’t need treatment. If they last longer or cause problems, then surgery may be recommended to drain the fluid surrounding your testicle.
The fluid can be aspirated (drained) using a needle, but this is only a temporary solution as the fluid will usually build up again.