A hernia occurs when an organ or tissue in the body leaves its normal anatomy and enters another part of the body through a congenital or acquired weak point, defect or orifice. Hernias mostly occur in the abdomen and are also known as extra-abdominal hernias. Extra-abdominal hernia: It is formed when an organ or tissue in the abdominal cavity, together with the peritoneal wall layer, protrudes through a weak point or aperture in the abdominal wall towards the body surface. Such as the most common inguinal hernia, there are also femoral hernia, umbilical hernia, incisional hernia, etc. Intra-abdominal hernia: formed when an organ or tissue enters the interstitial sac in the abdominal cavity, such as omental foramen hernia.