The belly button, or navel, is a unique reminder of our earliest connection to life. While some navels appear as a small indentation, known as an “innie,” others gently protrude outward, commonly referred to as an “outie.” This natural variation often sparks curiosity about its origins and why these differences exist. Understanding the process of belly button formation helps explain why some individuals develop an outie.
How Belly Buttons Form
The journey to forming a belly button begins before birth with the umbilical cord, a lifeline connecting a developing fetus to its mother’s placenta. This cord delivers oxygen and nutrients. After birth, the umbilical cord is clamped and cut, leaving a small stump attached to the newborn’s abdomen.
This remaining stump typically dries, shrivels, and darkens over a period of one to three weeks. Eventually, it detaches naturally. The area where the cord was attached then forms a scar, which becomes the belly button.
Common Reasons for an Outie
An outie belly button is a normal anatomical variation, occurring in approximately 10% of people. Its formation is primarily due to the way the skin and scar tissue heal after the umbilical cord stump falls off. Rather than the skin folding inward to create a concave appearance, the scar tissue or a small amount of the remaining umbilical tissue may protrude outward.
The appearance of an outie is not influenced by how the umbilical cord was cut or clamped at birth. Instead, factors such as the amount of residual umbilical tissue, the specific way the scar forms, or slight variations in the closure of the abdominal muscles can contribute to an outward-facing navel.
When an Outie is a Concern
For most individuals, an outie belly button is simply a cosmetic difference and does not pose health risks. However, in some rare instances, a protruding navel might be linked to an underlying condition, such as an umbilical hernia. An umbilical hernia occurs when a small portion of the intestine or fatty tissue pushes through a weak spot in the abdominal wall near the navel, creating a bulge.
These hernias are common in infants and often appear more noticeable when a baby cries, coughs, or strains. Most umbilical hernias in children are painless and typically close on their own by the time the child is four or five years old. While usually harmless, a healthcare provider should evaluate an umbilical hernia, especially if it becomes large, painful, red, or if the child experiences vomiting.