It’s a bulge that doesn’t belong. That’s how many people experience hernias, believed to be the most common cause of surgery in the United States. A hernia is a weakness or opening in the abdominal wall that allows part of an organ or any intra-abdominal contents to push through the opening. “Most people with hernias are born with them. You may have a hernia for years, and one day, when you lift something or move in a certain way, you notice th…