Umbilical hernia

This is a hole in the abdominal wall at the belly button, the location of the umbilical cord during fetal development. It usually closes by itself as it fills with scar tissue. Infants with a hernia here usually resolve by age 4-5. Adults may develop a hole here for unknown reasons, and will see a lump under the skin ("outie") where intra-abdominal contents have passed through the hole.