A hydrocele occurs when the scrotum fills with fluid and becomes heavy. A hydrocele occurs in males when fluid fills the scrotum, which is the sac under the penis that contains the testicles. Fluid can surround one or both testicles, causing swelling in the scrotum.
Hydrocele occurs when there is a collection of fluid inside the scrotum. This causes one of the testicles to look larger than the other. Hydroceles are often found.
In a small number of cases, a hydrocele is due to an underlying problem with a testicle (testis). A tube (the vas deferens) takes sperm from each testicle (testis) to the your penis. A hydrocele is a collection of fluid in a sac in your scrotum next to a testicle (testis).