A hiatal hernia occurs when the upper part of the stomach pushes up into the chest through a small opening in the diaphragm, the muscle that separates the abdomen from the chest.
Incisional hernias occur at or in close proximity to a surgical incision through which intestinal or other tissue protrudes. All abdominal surgery carries the risk of a postoperative incisional hernia due to a weakening of the muscle from the incision.
An umbilical hernia occurs at the umbilicus (belly button) when a loop of intestine pushes through the umbilical ring, a small opening in a fetus’ abdominal muscles through which the umbilical cord passes.
A ventral (abdominal) hernia is any protrusion of intestine or other tissue through a weakness or gap in the anterior abdominal wall. Umbilical and incisional hernias are specific and common types of ventral hernias.