What is Adult Hydrocele?

Male hydrocele is an excessive collection of fluid in a sac next to a testicle (testis). Most male hydroceles happen without an apparent reason.  Most male hydroceles are harmless and can be left alone. In a small number of cases, a male hydrocele is due to an underlying problem with a testis or other abdominal conditions. It usually occurs on one side but sometimes male hydroceles forms over both testicles (testes). Male hydrocele feels like a small fluid-filled balloon inside your scrotum. It feels smooth and is mainly in front of one of your testes. Male hydroceles vary greatly in size (usually 5 - 15cm). Very large male hydroceles are occationly seen in elderly men who do not seek medical advice. Male hydroceles usually enlarges over the years. Male hydroceles are normally painless. Large male hydroceles may cause discomfort because of their size. Walking, exercise, job, or sex may be affected. Majority of male hydroceles are without apparent cause (idiopathic). A small number of Male hydroceles are secondary to other diseases e.g. infection, inflammation, injury or tumours of the testis. Filariasis, a parasitic infection, accounts for most causes of hydroceles worldwide, affecting more than 120 million people in more than 73 countries. However, filariasis is rare in Hong Kong and in most developed countries. Sometimes, patients with excessive abdominal fluid can have hydroceles (e.g. peritoneal dialysis, liver failure or renal failure etc)

What is Female hydrocele?

FFemale hydrocele (Hydrocele of the canal of Nuck / Hydrocele of Nuck) is rare. It is an excessive collection of fluid in an abnormal formed peritoneal sac in the inguinal area or labium. It usually presents as a painless swelling.


The diagnosis is often confirmed by experienced surgeons via physical examination of the scrotum with a torch shining on the fluid (transillumination test). Medical imaging, e.g. ultrasound scan, CT scan, or MRI scan, is usually performed to confirm the diagnosis or rule out other possible causes.

Indication for surgery

Surgery is recommended if the hydrocele is large, causing discomfort, affecting activities of daily living, or causing unsightliness.


Traditional open hydrocele surgery requires a ~ 5cm incision. Mini-incision open surgery requires a 1.5cm – 2.5cm incision. Mini-incision open male hydrocele surgery required just a small cut in the scrotum. The fluid is then drained from around the testis. The sac containing the hydrocele fluid is partially excised, folded up, sutured and cauterized to prevent future collection of fluid. If there is any fluid communicating channel between the abdomen and the testis, it will be divided and ligated. Mini-incision open female hydrocele surgery required just a small cut in the medial groin area. The sac is opened and the fluid inside is drained. The sac is excised and the neck of the sac is ligated.

Postoperative events

Most patients undergoing elective surgical repair do very well and may be able to go home the same day or one day after surgery. The outcome of elective surgery are generally very good and the risk of complication is low. Oral analgesic and long acting local anesthetic are often used to reduce the postoperative wound pain to a minimum. Absorbable subcutaneous stitches are often used to close the wounds and there is no need to suffer any pain during removal of superficial stitches. Patients are usually required to keep the wound dry for 2 weeks. After 2 weeks, all the wound dressing can be removed. Patients can usually return to office work 1 to 2 weeks after surgery. Patients can often return to exercise 4 to 6 weeks after surgery. Needle aspiration of the hydrocele fluid is a temporary option to relieve the symptom. After this procedure, it is common for the sac of the hydrocele to refill with fluid in a few weeks to few months time. Sclerotherapy is the injection of sclerosant to seal the hydrocele sac after having it drained. The injection of sclerosant to the testis can cause lots of discomfort and complications. Therefore, needle aspiration and sclerotherapy are not commonly performed.

Frequently Asked Questions

Q: What is hydrocele? Is hydrocele a kind of cancer?
A: Hydrocele is a collection of fluid around the testes in the scrotum of boys (common) or in the groin/ lateral pubic area of girls (uncommon). Nearly all of the hydroceles are benign and are not cancer.

Q: Is it necessary to treat all hydroceles immediately?
A:  No. Hydroceles are usually asymptomatic at the beginning. If hydroceles are not treated, they usually will become larger and cause dragging discomfort. Large hydroceles may affect the normal activities of boys and girls. So, most hydroceles, which do not resolve after 18-24 months of observation, need surgery.