Hernias are by definition, a defect in the muscle container of the abdominal wall. That is, they are a gap, hole or defect in the abdominal wall. As a result of this hole or defect, the contents of the abdominal cavity, such as intestine, fat and other organs, may tend to be push through this hole by the normal pressure that occurs within the abdomen. As this material pushes through the hernia defect, a bulge or localized area of swelling will become evident beneath the skin of the abdominal wall. Since there are many Types of hernias, the site of this bulge will vary according to the type of hernia and location of the hole or defect. With activity such as exercise, coughing, lifting and straining etc., the pressure within the abdomen increases. As a result, more abdominal contents tend to push through the hernia symptoms defect, and the bulge gradually increases in size.