Posted in Web Hydrocele: Symptoms, Causes, Treatments, Surgery, & More January 11, 2021 A hydrocele is a swelling in the scrotum, the thin sac that holds the testicles. It happens when too much fluid builds up inside. The condition is most common in newborns, though it can happen to… https://www.webmd.com/parenting/baby/hydrocele-baby-boys