Hernia FAQs: Hernia occurs when part of an organ (intestine, bowel, bladder) or fatty tissue pushes through a weak spot or tear in the abdominal muscles. Inguinal hernias occur in the groin and hiatal hernias occur in the stomach. Causes include weakness in the abdominal wall, injury, surgery, family history, pregnancy, and obesity. Symptoms include pain and swelling. Treatment is usually surgical repair.