Hydrocele: A Clear Guide to Symptoms, Causes, and Treatment
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
A hydrocele is a harmless-feeling swelling caused by fluid collecting in the sac that surrounds a testicle [1]. It is very common in newborn boys and often clears up on its own by age 1. In older children and adults, it can follow an injury or inflammation in the scrotum. It is usually painless, but any scrotal swelling should be checked by a health care provider because it can be linked to a hernia, infection, or other treatable condition. Surgery removes a hydrocele when it does not resolve on its own [2].
Quick Answer
A hydrocele is a swelling of the scrotum caused by fluid collecting in the thin sac around a testicle. It is common in newborn boys and often goes away by age 1, while in adults it can follow injury or infection. It is usually painless, but a doctor should examine any scrotal swelling. Treatment ranges from watchful waiting to surgery.
What the research says
Many infant hydroceles resolve without surgery. In 174 infant boys with apparent communicating hydroceles who were observed instead of operated on right away, 69 of the 110 followed to an outcome (62.7%) had complete resolution without surgery, at an average age of 11.7 months. Forty-one (37.3%) had surgery because the hydrocele persisted or a hernia developed. Six boys developed a hernia during observation, and none had an incarceration (Koski et al., J Pediatr Surg, 2010 [3]).
Delay in treating a twisted testicle costs testicles. A systematic review and meta-analysis of 12 studies of testicular torsion in children found a mean early testicular loss rate of 39%, with late loss approaching 50%. Longer time before reaching hospital was a consistent predictor of poor outcomes, although study quality was generally low (MacDonald et al., J Pediatr Urol, 2018 [4]).
What Is a Hydrocele?
A hydrocele is a type of swelling in the scrotum, the pouch of skin that holds the testicles. The swelling happens when fluid collects in the thin sac that surrounds a testicle.
Hydroceles are common in newborns. In babies, they often go away without treatment by age 1. Older children and adults can develop a hydrocele due to an injury within the scrotum or other health problems.
A hydrocele often is not painful or harmful, and it might not need any treatment. Even so, it is important to see a health care provider if the scrotum looks swollen, because the swelling can signal a different, treatable problem.
Key fact | Detail |
What it is | Fluid collecting in the sac around a testicle |
Where it occurs | The scrotum, the pouch of skin holding the testicles |
Pronunciation | HI-droe-seel |
Who gets it | Common in newborn boys; also older children and adults |
Is it painful? | Often painless; pain can grow as swelling increases |
Typical baby outcome | Often resolves on its own by age 1 |
Symptoms: What to Watch For
Often the only sign of a hydrocele is painless swelling of one or both testicles. The swelling can occur on either side or both sides of the scrotum.
The swelling might make an adult's scrotum feel heavy. In general, pain gets worse as the swelling increases. Sometimes, the swollen area might be smaller in the morning and larger later in the day, a pattern seen when the fluid sac is open to the abdomen.
Symptom | How it typically feels |
Painless swelling | Often the only sign; one or both testicles |
Heaviness | The swollen scrotum feels heavy, especially in adults |
Growing pain | Pain generally increases as the swelling grows |
Size changes during the day | May be smaller in the morning, larger later in the day |
When to See a Doctor
See your health care provider if you or your child has swelling of the scrotum. It is important to find out whether other causes of the swelling are present that could be treated. For example, a hydrocele might be linked with a weak point in the abdominal muscles that allows part of the intestine to extend into the scrotum. This problem is called an inguinal hernia.
A baby's hydrocele often goes away on its own. But if your baby still has a hydrocele after a year, or if the swelling gets worse, ask your child's health care provider to check the hydrocele again.
Get help right away if you or your child has sudden, terrible pain or swelling in the scrotum. Prompt treatment is especially important if the pain or swelling starts within a few hours of an injury to the scrotum. These symptoms can happen with blocked blood flow in a twisted testicle, a problem called testicular torsion. Testicular torsion needs treatment within hours of the symptoms starting to save the testicle.
Situation | What to do |
Any scrotal swelling | See a health care provider to find the cause |
Baby with hydrocele after age 1, or worsening swelling | Have the child's provider re-check it |
Sudden, terrible pain or swelling | Get emergency help right away |
Swelling starting within hours of an injury | Get emergency help; possible testicular torsion |
What Causes a Hydrocele?
A hydrocele forms in different ways depending on age. In babies, it can form before birth. In older children and adults, it usually follows injury or inflammation.
Babies: How It Forms Before Birth
Typically, the testicles descend from the developing baby's abdominal area into the scrotum before birth. A sac comes with each testicle, letting fluid surround the testicles. Most often, each sac closes and the fluid is absorbed.
Sometimes, the fluid stays after the sac closes. This is called a noncommunicating hydrocele. The fluid usually is absorbed by age 1 or 2.
Other times, the sac stays open. This is called a communicating hydrocele. The sac can change size, or fluid can flow back into the abdominal area. Communicating hydroceles are often linked with an inguinal hernia.
Type | What happens | Typical outcome |
Noncommunicating | The sac closes but fluid stays inside | Usually absorbed by age 1 or 2 |
Communicating | The sac stays open; fluid can move | Can change size; often linked with inguinal hernia |
Older Children and Adults: Injury and Inflammation
In older children and adults, a hydrocele can form due to an injury to the scrotum. Or it can form because of inflammation, a type of swelling, within the scrotum. Inflammation might be caused by an infection in the testicle or in the small, coiled tube at the back of each testicle.
Risk Factors
Most hydroceles are present at birth. At least 5% of newborn males have a hydrocele. Premature babies — those born more than three weeks before their due dates — have a higher risk of having a hydrocele.
Risk factors for getting a hydrocele later in life include injury or inflammation within the scrotum, and infection, including a sexually transmitted infection.
Risk factor | How it raises risk |
Being a newborn male | At least 5% of newborn males have a hydrocele |
Being born premature | Babies born more than 3 weeks early have higher risk |
Injury in the scrotum | Injury can trigger fluid collection later in life |
Scrotal inflammation | Often from an infection in the testicle or the coiled tube behind it |
Infection, including STIs | Sexually transmitted infections can cause inflammation |
Possible Complications
A hydrocele often is not dangerous and usually does not affect the ability to have a baby. But a hydrocele might be linked with a health problem that can cause serious issues.
An infection or tumor might cause the testicles to make less sperm or not work as well as usual. An inguinal hernia can lead to life-threatening health problems if left untreated. This is why a medical checkup matters even when the swelling feels painless.
Possible complication | Why it matters |
Infection | May reduce sperm production or testicle function |
Tumor | May reduce sperm production or testicle function |
Inguinal hernia | Can lead to life-threatening health problems |
How a Hydrocele Is Diagnosed
Your health care provider should start with a physical exam. The exam is likely to include checking for pain in an enlarged scrotum, pressing on the abdominal area and scrotum to check for an inguinal hernia, and shining a light through the scrotum. If you or your child has a hydrocele, the light will show clear fluid surrounding the testicle. This simple light test is called transillumination.
After the exam, you may need blood and urine tests to help find out if you or your child has an infection. An imaging test called ultrasound may check for a hernia, a tumor, or other causes of swelling in the scrotum.
Test or step | What it checks |
Physical exam | Pain in an enlarged scrotum |
Pressing on abdomen and scrotum | Signs of an inguinal hernia |
Light test (transillumination) | Clear fluid around the testicle confirms hydrocele |
Blood and urine tests | Signs of an infection |
Ultrasound | A hernia, tumor, or other causes of swelling |
Treatment Options
In babies, a hydrocele sometimes goes away on its own. But at any age, it is important for a health care provider to check a hydrocele, because it can be linked to a problem with the testicles.
When Surgery Is Needed
A hydrocele that does not go away on its own might need to be removed with surgery. Some people do not have to stay at the hospital overnight after surgery, which makes this a common outpatient procedure.
Before the operation to remove a hydrocele, you receive medicine that keeps you from feeling pain. One type of medicine puts you in a sleep-like state as well. To remove the hydrocele, a surgeon makes a cut in the scrotum or the lower abdominal area.
Sometimes, a hydrocele is found during surgery to repair an inguinal hernia. In this case, the surgeon might remove the hydrocele even if it is causing no discomfort.
Treatment approach | When it is used |
Watchful waiting | Babies, since hydroceles often resolve on their own by age 1–2 |
Surgery (hydrocelectomy) | Hydrocele that does not resolve on its own, at any age |
Removal during hernia repair | Hydrocele found during inguinal hernia surgery, even without discomfort |
Recovery and Aftercare
After surgery, you might need a tube to drain fluid and a bulky bandage for a few days. You may need a follow-up exam, because a hydrocele might come back.
After surgery | What to expect |
Hospital stay | Many people go home the same day; an overnight stay is not always needed |
Drainage tube | May be needed to drain fluid for a few days |
Bandage | A bulky bandage supports the area for a few days |
Follow-up exam | Needed because the hydrocele might return |
Coping and What to Do in the Meantime
While you wait for an appointment, the safest step depends on your situation. If you are a sexually active adult, stay away from sexual contact that could put your partner at risk of getting a sexually transmitted infection. This includes sex, oral sex, and any skin-to-skin genital contact.
For babies, routine care continues as normal while the hydrocele resolves. If the swelling grows or the child shows any pain, contact your child's health care provider.
Preparing for Your Appointment
For a hydrocele, you might see a doctor called a urologist. A urologist is an expert in problems of the urinary and reproductive tract.
What You Can Do
Take note of your symptoms or your child's symptoms, and note how long they have lasted. List all medicines, vitamins, and supplements that you or your child takes, including the doses. A dose is how much you or your child takes. List key personal and medical information, including other health problems, recent life changes, and sources of stress. Prepare questions to ask your health care provider.
For hydrocele, some basic questions to ask your provider include: What do you think is causing this swelling? Are there any other possible causes? What kinds of tests are needed? What treatment do you recommend, if any? What symptoms will mean that it's time to treat this condition? Do you suggest any limits on activity?
Feel free to ask other questions that come up during your appointment.
Question to ask | Why it matters |
What do you think is causing this swelling? Are there other possible causes? | Frames the diagnostic possibilities |
What kinds of tests are needed? | Helps you prepare |
What treatment do you recommend, if any? | Sets expectations for next steps |
What symptoms mean it's time to treat this condition? | Defines watchful waiting vs. action |
Do you suggest any limits on activity? | Protects daily routine and work |
What to Expect From Your Doctor
Your health care provider is likely to ask you some questions.
If your child is affected, the provider might ask: When did you first notice this swelling? Has it increased over time? Is your child in any pain? Does your child have any other symptoms?
If you are affected, your provider might ask: When did you first notice the swelling? Have you had any discharge from your penis or blood in your semen? Do you have discomfort or pain in the affected area? Do you have pain during sex or when you ejaculate? Do you have a frequent or urgent need to pee, or does it hurt when you pee? Have you and your partner been tested for sexually transmitted infections? Do your hobbies or work involve heavy lifting? Have you ever had a urinary tract or prostate infection, or other prostate conditions? Have you ever had radiation or surgery in the affected area?
Who is affected | Sample questions the provider may ask |
A child | When was the swelling first noticed? Has it grown? Is there pain? Any other symptoms? |
An adult | When did it start? Any discharge or blood in semen? Pain with sex or urination? STI testing for you and your partner? Heavy lifting at work or in hobbies? Prior urinary, prostate, or surgical history in the area? |
Conclusion: Most Hydroceles Resolve — But Get Every Swelling Checked
A hydrocele is one of the more reassuring causes of scrotal swelling. It often causes no pain, usually does not affect fertility, and in babies frequently disappears on its own within the first two years of life. When it does not resolve, outpatient surgery reliably removes it, and recovery is quick for most people.
The important message is that the cause of any scrotal swelling deserves a professional answer. Swelling can signal an inguinal hernia, an infection, or a tumor, and sudden severe pain is a true emergency that must be treated within hours. If you or your child has scrotal swelling, make an appointment, and treat sudden, severe scrotal pain as a medical emergency.
Take the next step: Talk to a health care provider about any scrotal swelling, and seek emergency care right away for sudden, severe scrotal pain.
Frequently Asked Questions
What is a hydrocele?
A hydrocele is swelling in the scrotum caused by fluid collecting in the thin sac that surrounds a testicle. It is common in newborn boys and can also occur in older children and adults after an injury or inflammation in the scrotum.
Is a hydrocele dangerous?
Usually not. A hydrocele often is not painful or harmful and frequently goes away on its own in babies. However, a doctor should check any scrotal swelling because it can be linked to a hernia, infection, or tumor that needs treatment.
Do hydroceles in babies go away on their own?
Often, yes. In newborns, a hydrocele frequently resolves without treatment by age 1, and noncommunicating hydroceles are usually absorbed by age 1 or 2. If the hydrocele persists past a year or worsens, the child's provider should re-check it.
What is the difference between communicating and noncommunicating hydroceles?
In a noncommunicating hydrocele, the sac closes and fluid stays inside; it usually absorbs by age 1 or 2. In a communicating hydrocele, the sac stays open, can change size, and fluid can flow back into the abdomen. Communicating hydroceles are often linked with an inguinal hernia.
What causes a hydrocele in adults?
In older children and adults, a hydrocele can form due to an injury to the scrotum or inflammation from an infection in the testicle or the small, coiled tube at the back of the testicle. Sexually transmitted infections can also cause this inflammation.
Does a hydrocele cause pain?
Often the only sign is painless swelling, and the scrotum may feel heavy. Pain generally increases as the swelling grows, and the area can be smaller in the morning and larger later in the day.
How is a hydrocele diagnosed?
Diagnosis starts with a physical exam, including pressing on the abdomen and scrotum to check for a hernia and shining a light through the scrotum, which reveals clear fluid. Blood and urine tests check for infection, and ultrasound looks for a hernia, tumor, or other causes of swelling.
Is hydrocele surgery major surgery?
Not usually. Many people go home the same day without an overnight hospital stay. The surgeon makes a small cut in the scrotum or lower abdomen, and you may need a fluid drainage tube and a bulky bandage for a few days afterward.
Can a hydrocele come back after surgery?
Yes, it is possible. Because a hydrocele might return, a follow-up exam after treatment is recommended.
When is scrotal swelling an emergency?
Get help right away for sudden, terrible pain or swelling in the scrotum, especially within a few hours of an injury. This can signal testicular torsion — blocked blood flow in a twisted testicle — which must be treated within hours to save the testicle.
Related Reading
References
Mayo Clinic Staff. Hydrocele - Symptoms and causes. Mayo Clinic. December 23, 2025. https://www.mayoclinic.org/diseases-conditions/hydrocele/symptoms-causes/syc-20363969
Mayo Clinic Staff. Hydrocele - Diagnosis and treatment. Mayo Clinic. December 23, 2025. https://www.mayoclinic.org/diseases-conditions/hydrocele/diagnosis-treatment/drc-20363971
Koski ME, Makari JH, Adams MC, et al. Infant communicating hydroceles--do they need immediate repair or might some clinically resolve? J Pediatr Surg. 2010;45(3):590-593. PMID 20223325. https://doi.org/10.1016/j.jpedsurg.2009.06.026
MacDonald C, Kronfli R, Carachi R, O'Toole S. A systematic review and meta-analysis revealing realistic outcomes following paediatric torsion of testes. J Pediatr Urol. 2018;14(6):503-509. PMID 30404723. https://doi.org/10.1016/j.jpurol.2018.09.017
Medical disclaimer
This article is for educational purposes only and does not replace professional medical advice. Always consult a qualified healthcare provider for diagnosis and treatment.
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