A hydrocele is a collection of fluid in the scrotum. Most hydroceles go down within the first few months of life in babies so do not need treatment. If a hydrocele persists then a small operation can usually cure the problem.
The normal scrotum and testes
The scrotum is normally loose, soft and fleshy. It holds the two testicles (testes). Usually you can easily feel the testes in the scrotum. A tube (the vas deferens) takes sperm from each testicle (testis) to the penis. It is normal for one testis to hang lower than the other.
What is a hydrocele?
A hydrocele is a collection of fluid in a sac in the scrotum next to a testicle (testis). It usually occurs on one side but sometimes a hydrocele forms over both testicles (testes).
The normal testis is surrounded by a smooth protective tissue sac. You cannot normally feel this. It makes a small amount of 'lubricating' fluid to allow the testis to move freely. Excess fluid normally drains away into the veins in the scrotum. If the balance is altered between the amount of fluid that is made and the amount that is drained, some fluid accumulates as a hydrocele.
What do hydroceles look and feel like?
A hydrocele feels like a small fluid-filled balloon inside the scrotum. It feels smooth and is mainly in front of one of the testicles (testes). They can vary in size. Hydroceles are normally painless.
What causes hydroceles?
Some babies are born with a hydrocele. Hydroceles are very common in babies. When babies develop in the womb (uterus), the testicles (testes) move from the tummy (abdomen) to the scrotum. Sometimes the passage which allows this to happen does not close completely. This may then lead to a hydrocele developing.
Hydroceles can sometimes be associated with a hernia.
What is the treatment for hydrocele?
Hydroceles usually improve without any treatment within the first year of life. An operation is usually only advised if the hydrocele persists after 12-24 months of age.
If your child also has a hernia then this will usually be corrected in the same operation.
The operation for a hydrocele involves making a very small cut in the lower tummy (abdomen) or the scrotum. The fluid is then drained from around the testicle (testis). The passage between the abdomen and the scrotum will also be sealed off so the fluid cannot reform in the future. This is a minor operation and is performed as a day case, so does not usually involve an overnight stay in the hospital.
There are no long-term effects of having a hydrocele. Having a hydrocele does not affect the testicles (testes) or a boy's fertility in the future.
Further reading and references
Guidelines on Paediatric Urology; European Association of Urology (2015)