Common symptoms
- A smooth swelling, usually without pain, on one or both sides of the scrotum
- A heavy or dragging feeling, especially when the swelling is large
- In babies, a swelling that is smaller in the morning and bigger after crying or play, a sign of an open channel to the abdomen
- A swelling in the groin that comes and goes, which can mean a hernia
- Pain, redness and fever, which suggest infection rather than a simple hydrocele
- A hard lump felt in the testis itself, which needs prompt checking
When not to wait: Go to an emergency department at once for sudden, severe pain in a testis, which can be torsion (a twisted testis) and needs surgery within hours. A baby with a hard, tender groin or scrotal swelling who is vomiting or crying without stopping also needs emergency care.
What causes a hydrocele?
The testis sits in a thin sac with a little fluid that lets it move smoothly. A hydrocele forms when too much fluid collects in this sac. In Hindi it is often called andkosh mein pani bharna.
Before birth, each testis travels down from the abdomen to the scrotum through a channel that normally closes. If it stays open, fluid from the abdomen can flow into the scrotum, called a communicating hydrocele. If the opening is wider, a loop of bowel can come down too, which is an inguinal hernia.
In adults, most hydroceles have no clear cause and build up slowly over years. Some follow:
- An infection of the testis or epididymis (the coiled tube behind the testis)
- An injury to the scrotum
- Surgery in the groin, such as varicocele or hernia surgery
- Filariasis, a parasite infection spread by mosquitoes in some parts of India
- Rarely, a tumour of the testis
Hydrocele in babies and children
Many newborn boys have a hydrocele. In most, the channel closes and the fluid is absorbed during the first year or two, so the usual advice is to wait and watch. The swelling does not hurt and does not harm the testis.
Surgery is usually advised if the hydrocele is still present after about two years of age, if it keeps changing size (a sign that the channel is open), if it is very large, or if a hernia is found. A hernia is not left to wait, because bowel can get trapped. In children the operation is done through a small cut in the groin crease, where the open channel is tied off. See pediatric urology care and, if a testis is also missing from the scrotum, the undescended testis page.
Hydrocele in adults, and why the ultrasound matters
In adult men a hydrocele does not usually go away by itself. It may stay the same for years or slowly enlarge. A small hydrocele that causes no pain or trouble can simply be watched.
The doctor examines the scrotum and may shine a light through it: fluid lets light through, while a solid lump does not. An ultrasound of the scrotum is still advised for every new hydrocele in an adult. The fluid can make the testis impossible to feel, and the scan shows whether the testis underneath is normal. Testicular cancer is uncommon, but it mostly affects young men between about 15 and 40, and it can first show as a hydrocele. A lump in the testis needs prompt treatment; see testicular cancer surgery.
The scan also tells a hydrocele apart from other swellings: a hernia, an epididymal cyst, an infection or a varicocele, which is a group of swollen veins that feels like a bag of worms (see varicocele surgery). If filariasis is suspected, a blood test may be added.
When is hydrocele surgery advised?
Hydrocelectomy, the operation for a hydrocele in adults, is usually advised when:
- The swelling is large, heavy or uncomfortable
- It makes walking, sitting, cycling, work or sex difficult
- It keeps growing, or the skin of the scrotum is stretched or irritated
- You are bothered by its appearance
The operation is usually done under spinal or general anaesthesia and takes around 30-60 minutes. Through a cut in the scrotum, the sac around the testis is opened and drained, and then either removed or folded and stitched so that fluid cannot collect again. A small drain is sometimes left for a day. Many men go home the same day or the next day.
Why draining a hydrocele with a needle is not usually preferred
Drawing out the fluid with a needle (aspiration) seems simpler, but the sac is still there and the fluid usually comes back, often within weeks or months. Each puncture carries a small risk of infection and bleeding inside the scrotum. Aspiration should never be done before an ultrasound has checked the testis.
Sclerotherapy, in which a medicine is injected after draining to make the walls of the sac stick together, is an option for some men who are not fit for surgery. The fluid may still come back, the injection can be painful, and it can make later surgery more difficult, so it is discussed mainly when surgery is not suitable.
Recovery after hydrocele surgery
Swelling and bruising of the scrotum are normal and can take a few weeks to settle fully. Snug underwear or a scrotal support, and a cold pack wrapped in cloth for the first two days, help. Most men return to desk work in about a week and avoid heavy lifting, cycling and sex for about 2-4 weeks, as advised.
Possible problems include a collection of blood in the scrotum (haematoma), wound infection, swelling that lasts longer than expected, the hydrocele returning in a small number of men and, rarely, injury to the tube that carries sperm. Contact the clinic for fever, a swelling that grows fast or is very painful, or pus from the wound. Children usually recover within a few days. For other causes of scrotal pain, read the guide to testicular pain.
Tests that may be needed
- Examination of the scrotum, with a light shone through the swelling
- Ultrasound of the scrotum, which shows the fluid and checks the testis underneath
- Urine test if infection is suspected
- Blood test for filariasis in selected cases
- Tumour marker blood tests if the ultrasound shows a lump in the testis
Cost, insurance and government schemes
Cost depends on the procedure and your hospital stay. See how estimates, insurance and schemes work.
Frequently asked questions
Is a hydrocele dangerous?
A simple hydrocele is not dangerous and does not turn into cancer. It matters mainly because of discomfort, and because it can hide a problem in the testis, which is why an ultrasound is done.
Can a hydrocele go away without surgery?
In babies it often does, within the first year or two. In adults it usually stays or grows, and no medicine or diet is known to absorb the fluid.
Does a hydrocele affect fertility or sex?
A hydrocele itself does not usually affect sperm production or erections, though a large one can make sex uncomfortable. Surgery is done carefully to protect the tube that carries sperm. Fertility concerns can be discussed under men’s sexual health care.
Can a hydrocele come back after surgery?
It can, but this is uncommon after hydrocelectomy. It is much more likely after draining with a needle.
How is a hydrocele different from a hernia?
A hydrocele is fluid around the testis, and the doctor can usually feel normal tissue above it. A hernia is bowel or fat coming down from the abdomen; it often goes back when you lie down and gets bigger when you cough. In children both can come from the same open channel. An examination and ultrasound tell them apart.
My baby’s scrotum looks swollen. What should I do?
Show your child to a doctor. If the swelling is soft, does not hurt and the child is well, it is usually a hydrocele that can be watched. If the swelling is hard, tender or red, or the baby is vomiting, go to an emergency department at once.
This page is general information, not a diagnosis. Please read our medical disclaimer.