Southern Cross Medical Library

Southern Cross Medical Library

A hydrocoele (pronounced hi-dro-seel) is the build-up of fluid around the testicles, causing swelling in the scrotum.

Hydrocoeles can be present at birth or affect infants and children. They may also occur in adolescents or adults as a result of infection, inflammation, or injury to the testicles.

Hydrocoeles are a common cause of scrotal swelling and do not cause any damage to the testicles. Treatment can involve draining the fluid using a needle or minor surgery but hydrocoeles will often resolve themselves without treatment.

Signs and symptoms

A hydrocoele can occur on one side or on both sides of the scrotum but most commonly occur on the right side. Apart from the scrotal swelling associated with a hydrocoele, other signs characteristic of the condition include:

  • A bluish discolouration of the skin if the hydrocoele is large
  • Rise and fall in the size of the swelling (mainly in infants)
  • The area of the hydrocoele is clearly defined
  • Hydrocoeles are not usually painful but increasing size may cause discomfort.


The doctor will carefully examine the scrotal swelling. Shining a light on the area helps differentiate a hydrocoele from others causes of swelling, such as an inguinal hernia. With a hydrocoele, the presence of fluid will cause the scrotum to light up when a light is shone on the area (transillumination).

In adolescents and adults, further diagnostic tests may be recommended such as blood tests to exclude infection and ultrasound scanning to exclude hernia, testicular cancer, varicocoele, and other causes of swelling.

It is important for males of any age to have a hydrocoele checked out by a doctor because hydrocoeles can be a sign of a more serious problem with the testicles.


In infants, hydrocoeles may be the result of the passage through which the foetus’s testicle descends from the abdomen to the scrotum not sealing off properly. This allows fluid to flow from the abdomen into the scrotum.

Most infant hydrocoeles resolve without treatment by the age of 12–18 months. If the hydrocoele persists for longer than 18 months, treatment is usually recommended.

In adolescents and adults, treatment may not be required if the hydrocoele is small, the testes can be examined easily, and the amount of fluid remains constant. Treatment may be recommended if the hydrocoele is causing discomfort or embarrassment.

A hydrocoele can be treated by draining the fluid with a needle (aspiration). A “sclerosing” solution may be injected into the scrotum after the hydrocoele has been drained to seal off the passage from the abdomen, and prevent fluid from building up again.

Surgical removal of the hydrocoele (hydrocelectomy) may be recommended in cases where the hydrocoele is large and uncomfortable, or where it has recurred after aspiration. This is a minor surgical procedure that is performed on a day-stay basis. In infants a general anaesthetic is used. In adults a regional anaesthetic may be used.

During surgery a small incision is made in the scrotum or lower abdomen and the hydrocoele is drained of fluid. The incision is closed with small stitches. Surgery usually prevents recurrence of the hydrocoele.


Mayo Clinic (2018). Hydrocele (Web Page). Rochester, MN: Mayo Foundation for Medical Education and Research. [Accessed: 16/04/20]
O’Toole, M.T. (Ed.) (2017). Hydrocele. Mosby’s Dictionary of Medicine, Nursing & Health Professions (10th ed.). St Louis, MI: Elsevier.
Parke, J.C. (2020). Hydrocele (Web page). Medscape Drugs and Diseases. New York, NY: WebMD LLC. [Accessed: 16/04/20]

Last Reviewed – April 2020

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The purpose of the Southern Cross Medical Library is to provide information of a general nature to help you better understand certain medical conditions. Always seek specific medical advice for treatment appropriate to you. This information is not intended to relate specifically to insurance or healthcare services provided by Southern Cross.