Hydrocele

A hydrocele is swelling of the scrotum caused by fluid collecting within the thin sac surrounding a testicle. It is common in infants and often resolves on its own, while in adults it is important to rule out other underlying causes. ^[1][2][3]

What is a hydrocele?

A hydrocele is the buildup of fluid between the layers of tissue that surround the testicle, leading to swelling of the scrotum. The swelling is usually painless and is sometimes described as feeling like a water-filled balloon. In newborns and infants, it may be related to incomplete closure of the passage between the abdomen and groin. In adults, it can develop after inflammation, trauma, infection, or sometimes other scrotal problems. A hydrocele by itself is usually not dangerous, but not every scrotal swelling is a hydrocele, so sudden, painful, or hard swelling should be evaluated promptly. ^[1][2][3]

What are the symptoms?

The most common symptom is swelling of the scrotum on one or both sides. The swelling is often painless, but when it becomes larger it can create a feeling of heaviness, discomfort, or friction while walking. In infants, parents usually notice it during diaper changes. In adults, the size may seem to vary during the day, and there may be a stretching sensation or cosmetic discomfort. A hydrocele alone does not usually impair testicular function, but if pain, redness, fever, nausea, sudden enlargement, or a firm mass is present, urgent conditions other than hydrocele should also be considered. For that reason, assuming that painless swelling is always unimportant is not a safe approach. ^[1][2][3]

Why does it occur in infants and adults?

In infants, a hydrocele most often develops because the channel formed while the testicles descend from the abdomen into the scrotum does not fully close. If that opening remains, abdominal fluid can pass into the scrotum; this is called a communicating hydrocele. In many babies, the passage closes over time and the hydrocele disappears during the first year of life. In adults, inflammation, trauma, prior surgery, infections of the epididymis or testicle, and more rarely tumors may be associated. So although infant and adult hydroceles are described with the same word, the evaluation approach differs by age. ^[1][2][3]

How is it diagnosed?

Diagnosis usually begins with a physical examination. The clinician evaluates the nature of the scrotal swelling, whether it is tender, and whether any other findings are present. Some hydroceles can be supported by transillumination, a method in which light passes through the fluid, but this alone is not enough. If the swelling is large, if the testicle cannot be clearly assessed, or if another cause is suspected, scrotal ultrasound is requested. Ultrasound is very helpful for distinguishing a hydrocele from hernia, testicular torsion, varicocele, epididymitis, or a mass. Especially in adults with a newly developed hydrocele, imaging is important to evaluate the underlying cause. ^[1][2][3]

Is treatment necessary?

Not every hydrocele requires treatment. In infants, observation is often preferred because spontaneous improvement during the first year is common. However, if the hydrocele persists, becomes very large, or is associated with an inguinal hernia, surgery may be considered. In adults, small hydroceles that do not cause symptoms can sometimes also be monitored. On the other hand, cases that enlarge, cause discomfort, create cosmetic problems, or raise suspicion of another underlying issue may be treated surgically. Draining the fluid with a needle may provide temporary relief in some situations, but because the fluid often returns, it is usually not a permanent solution. ^[1][2][3]

How is hydrocele surgery planned?

The aim of surgical treatment is to correct the collected fluid and the structural problem causing it. In children with a communicating hydrocele, the open passage needs to be closed. In adults, the goal is usually to remove or repair the fluid-filled sac. As with any operation, there are risks such as bleeding, infection, recurrence, and temporary swelling, but results are generally good in appropriately selected patients. The timing of surgery depends on age, symptoms, the suspected cause, and ultrasound findings. For that reason, blanket statements such as “every hydrocele must be operated on immediately” or “none ever need treatment” are not accurate. ^[1][2][3]

When is urgent evaluation needed?

If there is sudden severe pain in the scrotum, nausea or vomiting, rapidly increasing swelling, redness, fever, or a feeling of hardness in the testicle, more urgent causes such as testicular torsion or infection should be considered rather than hydrocele alone. Testicular torsion in particular is a time-sensitive emergency. Painful scrotal swelling should therefore not be left untreated under the assumption that it may simply be a hydrocele. In an adult man, newly developed scrotal swelling also deserves urologic evaluation rather than self-diagnosis. ^[1][2][3]

Daily life and follow-up

When observation is chosen, it is important to watch for changes in size and seek reassessment if pain or firmness develops. After surgery, swelling may continue for a while, so following advice on rest, scrotal support, and follow-up visits matters. In adults, because other problems may underlie scrotal swelling, regular self-awareness and seeking care when symptoms change are important. Although a hydrocele is often benign, not every change in the scrotal area should be placed in the same category. ^[1][2][3]

What conditions can hydrocele be confused with?

Scrotal swelling does not occur only because of hydrocele. Inguinal hernia, varicocele, epididymitis, testicular torsion, and testicular tumors can create a similar appearance. If there is a hard mass, pain, redness, or sudden onset, causes other than hydrocele must be considered more strongly. For that reason, trying to identify scrotal swelling by comparing internet images is not safe. Examination and, when needed, ultrasound are very important for making the correct distinction. In infants too, parents should not assume that every swelling will simply go away on its own and should keep scheduled pediatric surgery or urology follow-up. ^[1][2][3]

Brief conclusion and safe guidance

A hydrocele is usually a benign fluid collection, but newly developed scrotal swelling in an adult should always be evaluated. In infants, many cases improve over time, but persistent, large, or hernia-related cases may need surgery. If there is sudden pain, nausea, fever, or rapidly increasing swelling, urgent care is important. The safest approach is to take hydrocele seriously without unnecessary fear and follow age-appropriate specialist evaluation. ^[1][2][3]

Why are infant and adult hydroceles evaluated differently?

A large proportion of infant hydroceles are related to development and can improve spontaneously over time. In adults, a newly developing hydrocele may be a sign of infection, trauma, or more rarely another testicular problem. So even though the same word is used, the approach changes with age. In children, watchful waiting may be reasonable, while in adults ultrasound and urologic assessment are more often planned earlier. An age-appropriate approach helps avoid unnecessary operations while also detecting causes that should not be missed. ^[1][2][3]

FAQ

Is a hydrocele dangerous?

Most hydroceles are not life-threatening, and in infants they may resolve spontaneously. However, because other causes of scrotal swelling exist, proper evaluation is important. ^[1][2][3]

Can a hydrocele go away on its own?

In infants, it often improves during the first year of life. In adults, observation or treatment depends on the underlying cause and the size of the hydrocele. ^[1][2][3]

Can a hydrocele cause infertility?

A hydrocele alone is not usually a direct cause of infertility, but if there are other accompanying testicular problems, separate evaluation may be needed. ^[1][2]

When is hydrocele surgery necessary?

Surgery may be considered for hydroceles that are growing, causing discomfort, persisting, or suggesting another underlying problem. ^[1][2][3]

Could scrotal pain still be a hydrocele?

It can be, but in sudden and severe pain, urgent causes such as torsion must be ruled out. In that situation, waiting is not appropriate. ^[1][2][3]