Causes
The cause of some hernias cannot be pinpointed, but many result from increased pressure within the abdomen, a weak spot in the abdominal wall, or a combination of the 2.
In adults, hiatus hernias commonly develop in pregnant women and overweight people due to the increased pressure on the abdominal wall.
In men, an inguinal hernia will commonly develop in the groin, specifically in a region called the inguinal canal. This is where the spermatic cord and blood vessels to the testicles pass out of the abdominal cavity and into the scrotum. A weakness in the abdominal tissues at this point can allow a loop of bowel to pass out of the abdomen by following the path of the spermatic cord (indirect inguinal hernia) or between the opening into the inguinal canal and the pubic bone (direct inguinal hernia).
In women, inguinal hernias are rare, but can develop where the tissue that binds the uterus exits from the abdomen and joins with the tissue surrounding the vaginal opening.
Umbilical hernias may be present at birth. In adults, they may develop when there is a weakness in the tissue in the umbilical area combined with increased pressure on the abdominal wall.