An inguinal hernia is when intestine, fat or other tissue squeezes through an opening or weak spot in the abdomen (stomach area). Typically, muscle or other tissue hold the tissues or organs in place. The hernia causes a lump in the groin or scrotum. Inguinal hernias are very common in children, especially in boys. Hernias can be congenital (present at birth) or develop later in life.
Hydroceles are different from hernias, but they look similar. A hydrocele is a build-up of abdominal fluid in the tunica vaginalis (the sac that surrounds the testicles within the scrotum). Most of the time, hydroceles go away on their own. Sometimes, fluid can travel between the scrotum and the abdomen through a small opening. This is called a communicating hydrocele. This happens when the tunica vaginalis does not close completely before birth. The size of the hydrocele can change, depending on how much fluid flows in and out of the scrotum.