A varicocele is an enlargement of veins in the scrotum. About 17 percent of boys between the ages of 13 and 25 years old have varicoceles. Almost 90 percent of the time they are present on the left testicle and occur during or after puberty. Typically, a varicocele is noticed by a physician during a routine testicular exam. The veins will feel like a “bag of worms” when the child is standing and may disappear when he is lying down. During periods of exercise, intense activity, hot weather or standing for a long time, a child may feel a heaviness or dullness in the scrotum. In most cases, boys have no symptoms at all and may not be aware that anything is wrong. If symptoms do arise, surgery will be required to remove the veins and repair the area.