Condition Basics

What is a hydrocele?

A hydrocele is a painless buildup of watery fluid around one or both testicles that causes the scrotum or groin area to swell. This swelling may be unsightly and uncomfortable, but it usually is not painful and generally is not dangerous. Although hydroceles are common in newborns, they can also occur at any age in later life.

What causes it?

The cause of most hydroceles is unknown.

Hydroceles in newborns may mean there is an opening between the abdomen and the scrotum. Normally such openings close before birth or shortly after.

Hydroceles that appear later in life may be caused by an injury or surgery to the scrotum or groin area. Or they can be caused by inflammation or infection of the epididymis or testicles. In rare cases, hydroceles may occur with cancer of the testicle or the left kidney. This type of hydrocele can occur at any age but is most common in men older than 40.

What are the symptoms?

Often a hydrocele does not cause symptoms. You may notice enlargement of your scrotum. Symptoms, when present, can include pain, swelling, or redness of the scrotum or a feeling of pressure at the base of the penis.

How is it diagnosed?

A hydrocele is usually diagnosed by an examination of the scrotum, which may appear enlarged. As part of the examination, your doctor will shine a light behind each testicle (transillumination). This is to check for solid masses that may be caused by other problems, such as cancer of the testicle. Hydroceles are filled with fluid, so light will shine through them. Light will not pass through solid masses that may be caused by other problems, such as cancer. An ultrasound may be used to confirm the diagnosis of a hydrocele.

How is a hydrocele treated?

Hydroceles are not usually dangerous and are treated only when they cause pain or embarrassment or when they decrease the blood supply to the penis (rare). Treatment is not usually needed if a hydrocele does not change in size or gets smaller as the body reabsorbs the fluid. Hydroceles in men younger than 65 may go away by themselves. But hydroceles in older men do not usually go away.

Fluid can also be removed from a hydrocele with a needle (aspiration). But hydroceles that are aspirated often return, and surgery may then be needed. Aspiration is recommended only for men who are not physically able to have surgery because of the risk of infection and recurrence.

If the hydrocele gets larger or causes discomfort, surgery to remove the hydrocele (hydrocelectomy) may be needed.