It is an accumulation of fluid around the testicle. In young children, this condition is usually caused by an incomplete closure of the abdominal cavity / scrotum connection. It is best to make a surgical correction for this. In adults, the hydrocoele usually develops due to an imbalance in the production and absorption of moisture around the testicle, which can have various causes (infection, trauma, ...). In adults, a surgical correction should therefore only be performed in the event of complaints. This is done via a scrotum incision (3 cm), which can usually be done via day clinic.