What is 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.

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.

A hydrocele is usually diagnosed by an exam of the scrotum, which may appear enlarged. As part of the exam, 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.

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.

• Most of the time, all you need to do is watch for any changes in the swelling.