Hydrocele, pronounced as (hi-droe-seel), is when fluid fills a male’s scrotum, resulting in swelling. A hydrocele usually affects one testicle, however it can also affect both testicles.

A smooth protective tissue sac surrounds the normal testis which produces a small amount of lubricating fluid to allow the testis to move freely. Normally, excessive fluid is drained away into the veins in your scrotum. Some fluid accumulates as a hydrocele when the ratio between the amount of fluid produced and the amount that is drained is disrupted. A hydrocele feels like a small fluid-filled balloon inside your scrotum. The majority of these appear for no apparent reason, are innocuous, and might not require any treatment at all. Nevertheless, to be on the safe side, it’s still highly advised that you consult a doctor to rule out other cases. It is usually painless, but larger ones may cause discomfort, especially during sex, and can be embarrassing.

How common is it?

A hydrocele affects about 10% of newborn male newborns, but it usually goes away without treatment within the first year of life. Women can experience a hydrocele along the canalof Nuck, but it is very uncommon. Hydroceles occur in only about 1% of adult men over the age of 40 years.

The types of hydrocele.

There are two types of hydrocele:

  • Communicating hydrocele: This is the type of hydrocele that has contact (communication) with the fluids of the abdominal cavity and is caused by the failure of the processus vaginalis. If this membrane remains open, there is a potential for both a hernia and a hydrocele to develop. The scrotum will appear swollen and may change in size throughout the day.
  • Non-communicating hydrocele: In this case, the inguinal canal did close but there is still extra fluid around the testicle in the scrotum. This condition might be present at birth or might develop years later for no apparent reason. The size usually stays the same or grows very slowly.

What causes it?

The age of a person determines the cause of a hydrocele.

In babies

The testicles of a male infant descend from his abdomen into the scrotum towards the end of pregnancy. Each testicle is joined by a sac that allows fluid to surround the testicles. Once the testicles have moved into their normal position, the scrotum closes. If the scrotum stays open or reopens, fluid can pass from the belly to the scrotum through this canal, and this causes a hydrocele (non-communicating). Premature babies or babies that are born before the testicles have descended are at an increased risk of developing a hydrocele.

In adults

Hydroceles (communicating) that form later in life among men over the age of 40 are most likely because the inguinal ring has re-opened or has not closed up, causing fluid to move from the abdomen into the scrotum. Besides that, it can be developed as a result of an injury or inflammation within the scrotum. Inflammation might be caused by an infection, including a sexually transmitted infection (STI) in the testicle or in the small, coiled tube at the back of each testicle (epididymitis). When there is extensive swelling of the lower half of your body due to fluid retention, hydroceles can also be formed.

The Symptoms

Hydroceles are usually painless, with just a swelling scrotum (one or both testicles) being the only symptom. As mentioned previously, a man experiencing hydrocele may feel like there is a small balloon filled with fluid inside his scrotum. For some adult men, there may be a heavy sensation in the scrotum which might cause a bit of discomfort. How heavy the scrotum feels depends on the amount of fluid in the hydrocele. In some cases, the swelling might be worse in the morning than in the evening.  

When to seek medical help?

If you have sudden scrotal pain or swelling, especially within several hours of a scrotal injury, seek medical attention immediately! A variety of underlying medical conditions can trigger these signs and symptoms, including testicular torsion, in which blood flow is blocked in a twisted testicle. To save the testicle, testicular torsion must be treated within hours of the onset of symptoms.


A doctor will examine your testicles (testes) by shinning a light through your scrotum to determine if there’s fluid in the scrotum. This procedure is known as transillumination. If fluid is present, the scrotum will allow light transmission and the scrotum will appear to ‘light up’ with the light passing through. The light will not shine through the scrotum if the swelling is caused by a solid mass (cancer). Transillumination can help doctors figure out what’s causing scrotal swelling, but there are a few other techniques they can take to get a definitive diagnosis. If a clinician has any doubts regarding the underlying cause of the swelling, they may opt to schedule another test, such as an ultrasound scan of your testes. In some circumstances, exploratory surgery may be the only method to figure out what’s causing this symptom.

What are the treatment options?


If your newborn child has a hydrocele, it will most likely go away on its own within a year. On the other hand, if it does not go away on its own, or grows larger in size, he needs to be referred to a pediatric urologist for surgery. For adults, surgery is recommended if your hydrocele is large or uncomfortable. It involves making a very small cut in the scrotum or lower abdominal wall to drain fluid from around the testicle (testes). The passage between the abdomen and the scrotum will then be sealed off to prevent fluid from reforming in the future.

Needle aspiration

Your doctor can also easily drain the fluid with a needle and a syringe. To make the whole process bearable, local anaesthetic will be injected into the overlaying skin. However, the downside to this method is that it is common for the hydrocele’s sac to refill with fluid again within a few months after this treatment. The common side effects for this procedure are temporary pain in the scrotum as well as the risk of infection.


It is the injection of a solution to stop the hydrocele from recurring after the drainage procedure. This is rarely undertaken but may be recommended to patients who are not fit for surgery.