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The navel (clinically known as the umbilicus, colloquially known as the belly button, or tummy button) is a protruding, flat, or hollowed area on the abdomen at the attachment site of the umbilical cord.[1] All placental mammals have a navel.[2]

Human navel, female.jpg
The navel is a protruding, flat or hollowed scar left after the umbilical cord detaches.
PrecursorUmbilical cord
Ductus venosus[citation needed]
ArteryUmbilical artery
VeinUmbilical vein
Anatomical terminology



The navel is the centre of the circle in this drawing of the Vitruvian Man by Leonardo da Vinci

The umbilicus is used to visually separate the abdomen into quadrants.[3]

The umbilicus is a prominent scar on the abdomen, with its position being relatively consistent among humans. The skin around the waist at the level of the umbilicus is supplied by the tenth thoracic spinal nerve (T10 dermatome). The umbilicus itself typically lies at a vertical level corresponding to the junction between the L3 and L4 vertebrae,[4] with a normal variation among people between the L3 and L5 vertebrae.[5]

Parts of the adult navel include the "umbilical cord remnant" or "umbilical tip", which is the scar left by the detachment of the umbilical cord. This is located in the centre of the navel, sometimes described as the button. Attached round the umbilical cord remnant, is the "umbilical collar", formed by the dense fibrous umbilical ring. Surrounding this is the periumbilical skin. Directly behind the navel is a thick fibrous cord formed from the umbilical cord, called the urachus, which originates from the bladder.[6]


Although the navel is unique to each individual due to its being a scar, various general forms have been classified by medical practitioners.[7][8]

  • Outie: A navel consisting of the umbilical tip protruding past the periumbilical skin is an outie, essentially any navel which is not concave. A study taken of 1008 individuals aged at least 19 years old found that 49% have outies.[9]
  • Round shaped: Round navels are completely circular with no hooding.
  • Vertical shaped: Some navels present in the form of a more elongate hollow parallel with the linea alba.
  • Oval: This form consists of three variants; superior hooding, inferior hooding, no hooding.
  • T-shaped: As the name states, the scar is in the shape of a T, and may have superior hooding to various extent.
  • Horizontal: The scar is least visible as the natural lines of the tendinous intersection fold over the scar.
  • Swirly/Swirl: An unusual form in which the umbilical scar literally forms a swirl shape.
  • Distorted: Any navel which does not fit well into any of the other categories.

Clinical significanceEdit

The navel of an adult male a few days after a laparoscopic procedure to remove the appendix.


Outies are sometimes mistaken for umbilical hernias, however, they are a completely different shape with no health concern, unlike an umbilical hernia. The navel (specifically abdominal wall) would be considered an umbilical hernia if the protrusion was 5 centimeters or more. The total diameter of an umbilical hernia is usually 10 centimeters.[9] Navels that are concave are nicknamed "innies".[10] While the shape of the human navel may be affected by long term changes to diet and exercise, unexpected change in shape may be the result of ascites.[11]

In addition to change in shape being a possible side effect from ascites and umbilical hernias, the navel can be involved in umbilical sinus or fistula, which in rare cases can lead to menstrual or fecal discharge from the navel. Menstrual discharge from the umbilicus is a rare disorder associated with umbilical endometriosis.[12][13]

Other disordersEdit


To minimize scarring, the navel is a recommended site of incision for various surgeries, including transgastric appendicectomy,[16] gall bladder surgery,[17] and the umbilicoplasty[18] procedure itself.


Abdominal thrusts is a first aid method of dislodging an object stuck in the throat, and is performed just above the navel.[19]

Fashion, society and cultureEdit

The public exposure of the male and female midriff and bare navel was considered taboo at times in the past in Western cultures, being considered immodest or indecent. Female navel exposure was banned in some jurisdictions but community perceptions have changed to this now being acceptable.[20] The crop top is a shirt that often exposes the belly button when worn, and has become more common among younger-aged women. Exposure of the male navel has rarely been stigmatised and has become particularly popular in recent years due to the strong resurgence of the male crop top and male navel piercing[21] The navel and midriff are often also displayed in bikinis or when low-rise jeans are worn.

While the West was relatively resistant to navel-baring clothing until the 1980s, it has long been a fashion with Indian women.[22] Often displayed with Saris or Lehengas.

The Japanese have long had a special regard for the navel. During the early Jōmon period in northern Japan, three small balls indicating the breasts and navel were pasted onto flat clay objects to represent the female body. The navel was exaggerated in size, informed by the belief that the navel symbolized the center where life began.[23]

In Mediterranean culture, belly dancing is a popular art form that consists of dance movements focused on the torso and navel.

See alsoEdit


  1. ^ "Definition of NAVEL".
  2. ^ "Why don't other animals have belly buttons like ours?". Retrieved May 27, 2017.
  3. ^ "Anatomy & Physiology". Openstax college at Connexions. Retrieved November 16, 2013.
  4. ^ Ellis, Harold (2006). Clinical Anatomy: Applied Anatomy for Students and Junior Doctors. New York: Wiley. ISBN 1-4051-3804-1.[page needed]
  5. ^ O'Rahilly, Ronan; Müller, Fabiola; Carpenter, Stanley; Swenson, Rand (2004). "Abdominal walls". Basic Human Anatomy: A Regional Study of Human Structure. Dartmouth Medical School.
  6. ^ Khati, Nadia J.; Enquist, Erik G.; Javitt, Marcia C. (1998). "Imaging of the Umbilicus and Periumbilical Region". Radiographics. 18 (2): 413–4.
  7. ^ Shiffman, Melvin (2017). "7.3". Adult Umbilical Reconstruction: Principles and Techniques. Switzerland: Springer. p. 53. ISBN 978-3-319-43885-6.
  8. ^ Mohamed, Fahmy (2018). Umbilicus Types and Shapes. Egypt: Springer. pp. 105–8. doi:10.1007/978-3-319-62383-2_22.
  9. ^ a b Meier, Donald E.; OlaOlorun, David A.; Omodele, Rachael A.; Nkor, Sunday K.; Tarpley, John L. (2001). "Incidence of Umbilical Hernia in African Children: Redefinition of 'Normal' and Reevaluation of Indications for Repair". World Journal of Surgery. 25 (5): 645–8. doi:10.1007/s002680020072. PMID 11369993.
  10. ^ Ceccanti, Silvia, et al. "Umbilical cord sparing technique for repair of congenital hernia into the cord and small omphalocele." Journal of Pediatric Surgery 52.1 (2017): 192-196.
  11. ^ Herrine, Steven K. "Ascites". The Merck Manuals.
  12. ^ Bagade, Pallavi V; Guirguis, Mamdouh M (2009). "Menstruating from the umbilicus as a rare case of primary umbilical endometriosis: a case report". Journal of Medical Case Reports. 3: 9326. doi:10.1186/1752-1947-3-9326. PMC 2803849. PMID 20062755.
  13. ^ D'Alessandro, Donna M. (June 2, 2008). "What's Wrong With His Belly Button?".[self-published source?][unreliable medical source?]
  14. ^ Cunningham, F. Williams Obstetrics:The Newborn (24 ed.). McGraw-Hill. |access-date= requires |url= (help)
  15. ^ Fleisher, Gary R. Textbook of Pediatric Emergency Medicine. Philadelphia: Lippincott Williams & Wilkins, 2006, p. 928.
  16. ^ Kaehler, G.; Schoenberg, M. B.; Kienle, P.; Post, S.; Magdeburg, R. (2013). "Transgastric appendicectomy". British Journal of Surgery. 100 (7): 911–5. doi:10.1002/bjs.9115. PMID 23575528. Lay summaryMedical News Today (April 12, 2013).
  17. ^ "SRMC Surgeon Offers Gallbladder Removal through Belly Button Incision with da Vinci® System" (Press release). Southeastern Health. December 9, 2013. Retrieved August 16, 2015.
  18. ^ Bruekers, Sven E.; van der Lei, Berend; Tan, Tik L.; Luijendijk, Roland W.; Stevens, Hieronymus P. J. D. (2009). "'Scarless' Umbilicoplasty". Annals of Plastic Surgery. 63 (1): 15–20. doi:10.1097/SAP.0b013e3181877b60. PMID 19546666.
  19. ^ MedlinePlus Encyclopedia Abdominal thrusts
  20. ^ "New code may reveal navel". Mohave Daily Miner. 24 March 1985. Retrieved 20 April 2012.
  21. ^ "Crop Top Comeback". BBC. 28 August 2018. Retrieved 14 September 2018.
  22. ^ Banerjee, Mukulika & Miller, Daniel (2003) The Sari. Oxford; New York: Berg ISBN 1-85973-732-3[page needed]
  23. ^ Naumann, Nelly (2000). "First Indications of Symbolic Expression". Japanese Prehistory: The Material and Spiritual Culture of the Jōmon Period. Otto Harrassowitz Verlag. pp. 114–5. ISBN 978-3-447-04329-8.

Further readingEdit