Why do we have a belly button? Uncovering the umbilical connection

September 24, 2025 •

3 min read

A little-known fact is that the belly button is our very first scar, a permanent reminder of our connection to our mothers. This seemingly simple dimple holds the answer to the question: Why do we have a belly button?

Quick Summary

The belly button, or navel, is the scar left after the umbilical cord, which connected a fetus to its mother, is cut at birth. It served a crucial function during fetal development but has no physiological purpose in an adult. Its unique appearance varies from person to person.

Key Points

Fetal Lifeline: The belly button is the remnant of the umbilical cord, which provided vital nutrients and oxygen to a fetus in the womb from the placenta.
Post-Birth Scar: After the umbilical cord is cut, the leftover stump shrivels and falls off, leaving behind the belly button as a scar.
Innie vs. Outie: The shape of your navel is a result of how the scar tissue heals, not how the cord was cut. Outies can sometimes result from a minor umbilical hernia.
Internal Connections: Though non-functional in adults, internal ligaments from the original umbilical cord connect to the liver and bladder.
Medical and Aesthetic Use: The navel serves as an anatomical landmark for doctors and is a common site for laparoscopic surgery incisions and piercings.
Hygiene and Microbiome: The belly button is home to a unique community of bacteria and requires regular cleaning to prevent odor, infections, and the buildup of lint and other debris.

The Umbilical Lifeline: A Fetal Connection

Understanding the belly button requires looking back to fetal development. The umbilical cord connected the fetus to the placenta, acting as a lifeline for oxygen and nutrients. It also carried waste products away from the fetus. This essential structure contained one umbilical vein carrying oxygenated blood and two umbilical arteries carrying deoxygenated blood, all protected by Wharton's Jelly.

From Stump to Scar: The Healing Process

At birth, the umbilical cord is no longer needed and is cut, leaving a stump attached to the baby. This stump dries and falls off within a couple of weeks, leaving the belly button as a scar. The way this scar heals determines the navel's appearance.

The Adult Navel: More Than a Mark

While the adult belly button has no physiological function, remnants of the umbilical cord's internal structures remain as ligaments connected to the liver and bladder. The navel is a useful anatomical landmark for medical professionals and can be used as a surgical access point in laparoscopic procedures. It is also a common site for piercings.

The Belly Button Microbiome and Hygiene

The belly button hosts a unique microbiome of bacteria. Due to its structure, it can collect debris like lint, skin cells, and sweat, potentially leading to odor or infection. Belly button lint is often caused by clothing fibers trapped by abdominal hair and funneled into the navel. Regular cleaning with soap and water is important for hygiene.

Variations, Concerns, and Medical Use

The Great Innie vs. Outie Debate

The shape of the navel is determined by the healing process of the umbilical stump, not how the cord was cut. Most people have an 'innie' (concave), while about 10% have an 'outie' (convex), which can sometimes be due to a minor umbilical hernia. The healing process dictates the final appearance.


Feature	Innie (Concave)	Outie (Convex)
Appearance	A depression or indentation in the abdomen.	A protruding knob of skin.
Prevalence	Approximately 90% of the population.	Approximately 10% of the population.
Formation	Normal healing and scarring of the umbilical stump.	A variation in the scarring process, sometimes involving a minor umbilical hernia.
Hygiene	Requires careful cleaning to prevent debris buildup and potential odor.	Easier to clean due to less hidden surface area.

Potential Concerns and Solutions

Omphalophobia: Fear of belly buttons.
Infections: Can occur, especially with piercings, and require medical attention.
Umbilical Hernia: Intestine protrusion at the navel; often resolves in infants but may need surgery.

Laparoscopic Surgery

The navel is a common entry point for laparoscopic surgery, a minimally invasive technique that uses small incisions. This method offers benefits like reduced scarring and faster recovery. The Cleveland Clinic provides more information on this procedure [https://my.clevelandclinic.org/health/treatments/23114-laparoscopic-surgery].

Conclusion: A Mark of Our Origin

The belly button is a permanent scar signifying our initial connection to our mothers via the umbilical cord. While its primary function ends at birth, it remains an anatomical landmark and a testament to our development. Its various forms and microbial life highlight the unique aspects of even the most commonplace body parts.

Frequently Asked Questions

After birth, the belly button, or navel, serves no physiological purpose. It is simply the scar left from the umbilical cord. However, it is a useful anatomical landmark for doctors and an access point for certain types of surgery.

Almost all placental mammals, including humans, have a belly button because they had an umbilical cord. However, some people may not have a typical navel due to surgical procedures, such as a tummy tuck or correction of a congenital condition like a hernia.

The shape of your navel is determined by how the umbilical cord scar heals. It is not caused by how the doctor clamps or cuts the cord. An 'outie' can be caused by extra scar tissue or a small umbilical hernia.

Belly button lint is typically caused by abdominal hair trapping loose fibers from clothing and directing them into the navel. The movement of your body helps funnel these fibers, along with dead skin cells and sweat, into a compact mass.

To clean your navel, use a gentle soap and water during your regular bath or shower. For an 'innie,' you can use a moistened cotton swab to gently clean the inner folds. Always ensure you dry the area thoroughly to prevent bacterial growth.

In adults, the skin of the belly button is not directly connected to internal organs. However, inside the abdomen, the remnant blood vessels of the umbilical cord form ligaments that attach to the liver and bladder.

Belly button piercings, particularly 'outies' with protruding scar tissue, carry risks of infection, scarring, and rejection. It is important to go to a professional piercer who follows strict hygiene protocols. Consult a healthcare provider if you have any health concerns.