A hydrocele occurs when clear fluid builds up inside the sac surrounding the testicle, causing painless swelling on one or both sides of the scrotum. It usually develops gradually and, in adults, is often linked to disruption of the body's natural fluid balance — sometimes from prior injury, inflammation, or infection. While hydroceles are generally not dangerous, they should be evaluated by a surgeon to rule out other conditions such as hernia, infection, or testicular tumors. Hydrocelectomy removes the fluid-filled sac and prevents fluid from collecting again, offering a permanent solution with a high success rate.