An abnormal accumulation of fluid between the double-layered membrane that surrounds the testis

  • Most common in infants and the elderly
  • Genetics and lifestyle are not significant factors

The double-layered membrane that surrounds each testis normally contains a small amount of fluid. If an excessive amount of fluid accumulates within this membrane, a swelling called a hydrocele will result. This condition is most common in infant boys and elderly men. In most cases, there is no apparent cause, but hydroceles have been linked to infection, inflammation, or injury to the testis. Rarely, a hydrocele that develops in adulthood is due to a tumour in the testis (see Cancer of the testis).

A hydrocele usually develops as a visible swelling in the scrotum. There may be a heavy, dragging sensation in the scrotum due to its increased size, but the swelling is not normally painful.


If fluid accumulates in the double-layered membrane enclosing the testis, it forms a swelling in the scrotum called a hydrocele.

What might be done?

If you think you may have a hydrocele, you should consult your doctor. He or she will first try to identify a hydrocele by holding a torch against the affected area of your scrotum. If the swelling is due to excess fluid, light will shine through the swelling. Ultrasound scanning of the scrotum may also be used to confirm the diagnosis and to exclude an underlying testicular disorder such as a tumour.

Hydroceles that develop in infants often subside by the age of 6 months without needing treatment. In all cases, if a hydrocele becomes uncomfortable or painful, it may be treated by a minor operation in which the sac containing the excess fluid is removed. Alternatively, the fluid may be drained using a hollow needle, and a sclerosant (a substance that makes the layers of the membrane stick together) may be injected to prevent the hydrocele from recurring.

If the hydrocele is linked to an infection, an antibiotic may be prescribed. If a tumour is found, you will be referred for further tests and treatment.

Treatment: Vasectomy

From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.

The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.

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