Two causes of swelling of the scrotum include hydrocele and varicocele. A hydrocele is fluid build-up around the testicle(s), while a varicocele occurs when blood backs up in the main veins that drain the scrotum. Hydroceles occur in two forms, communicating and noncommunicating. Communicating hydroceles are associated with hernias and are usually seen in baby boys. Noncommunicating hydroceles are collections of fluid around the testicle and may occur at any age. Varicoceles are most common among teenagers and adult men.

Both conditions are usually painless. In infants, noncommunicating hydroceles often resolve in the first year of life and require no treatment. Communicating hydroceles do not tend to resolve and need correction. Varicoceles increase the risk of infertility and are generally treated if they occur in adolescents or infertile men. In any event, it is important to see your doctor for a diagnosis if you or your baby boy develops a swelling in the scrotum.


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A communicating hydrocele occurs when the channel that connects the scrotum to the abdomen (which allows the testicles to descend in baby boys) does not close up properly. This allows fluid to “leak” into the scrotum. Noncommunicating hydroceles occur when fluid builds up within the tissues that surround the testicle. Hydroceles may also be caused by injury or infection in the scrotal area, or by a testicular tumor.

A varicocele occurs when the valve in the main vein of the scrotum doesn’t work properly, allowing blood to back up. Varicoceles are rarely caused by kidney tumors , or other tumors in the location of the kidney (retroperitoneum).

Risk Factors

Many newborn boys will develop a hydrocele. Communicating hydroceles are more common in premature babies. They are also more common in children who are being treated for excess fluid in the brain (by draining the fluid into the abdomen), or who have an abdominal dialysis catheter.

Varicoceles typically develop in men between the ages of 15-25.


If you experience any of these symptoms, do not assume it is due to hydrocele or varicocele. These symptoms may be caused by other, sometimes serious, health conditions. If you experience any one of them, see your physician:

  • In adults:
    • Painless swelling—The primary symptom of an adult hydrocele is a painless swelling in one or both sides of the scrotum, which feels like a water-filled balloon. This may be accompanied by a persistent ache or feeling of heaviness in the scrotum.
  • In infants:
    • Painless swelling—In infants, the main symptom of a hydrocele is painless swelling of the scrotum. If the hydrocele is communicating (associated with a hernia), the amount of swelling will vary with activities such as crying.
  • Enlarged or twisted vein in the scrotum—A varicocele generally appears as a visible or palpable (able to be felt) enlarged or twisted vein in the scrotum. It may be associated with shrinkage (atrophy) of the testicle(s) and/or infertility. Varicoceles typically change in size, and are larger when standing or straining. Varicoceles occur more commonly on the left side. Some warning signs that a varicocele may be due to a tumor are sudden onset, right-sided location, or failure of the varicocele to become smaller when lying down.


Your doctor will ask about your symptoms and medical history, and perform a physical exam. Hydroceles and varicoceles are usually easily palpable. Your doctor will want to be sure there is no evidence of a testicular mass (eg, cancer). Tests may include the following:

  • Transillumination—A flashlight is shone through the enlarged portion of the scrotum; if a hydrocele is present, the scrotum will light up.
  • Ultrasound —a test that uses sound waves to examine the contents of the scrotum
  • Urinalysis tests
  • Testicular scintigraphy—A radioactive substance is injected into the blood, and x-rays are taken.


Treatment options include the following:


Surgical repair is recommended if the condition:

  • Persists beyond the first year of life,
  • Becomes large enough to threaten a testicle's blood supply, or
  • Is associated with a hernia , also known as a communicating hydrocele

Sclerotherapy can also be used for adult (noncommunicating) hydroceles, in which the fluid is removed through a needle and replaced with a substance that causes scarring. This is generally less effective than surgery.


Treatment is not required for all varicoceles; however, it is generally recommended if a varicocele is felt to be the cause of infertility . Treatment options include:

  • Open surgery—The vein is surgically cut and tied off.
  • Catheter ablation—Heat is applied through a catheter to destroy the vein.
  • Catheter embolization—A substance is placed in the vein to block it.
  • Laparoscopy —This involves the use of a thin, lighted tube inserted into the abdomen to view the vessels in the body as they lead to the testicle.

If you are diagnosed with a varicocele or hydrocele, follow your doctor's instructions .


There is no way to prevent varicoceles in adults or hydroceles in baby boys . Adult males can prevent traumatic hydrocele by avoiding injury to the scrotum.