Pectus Carinatum Causes and What You Can Do About It

by Dakota Brace

Pectus carinatum is a structural condition where the breastbone protrudes from the rest of the chest due to the overgrowth of the breastbone cartilage. It is a congenital disease, meaning that it is present from birth, although it becomes more obvious during early puberty. It can vary in both severity and presentation (symmetric vs. asymmetric; whether the upper or lower part of the chest protrudes).

One common side effect of pectus carinatum is rib flaring, where the lower ribs are also pushed outward or “flared.” Pectus carinatum is surprisingly common, occurring an average of once every 1500 births (0.07%).[1] This means that over 100,000 people are living with this condition in the United States alone. 

Chicken Breast vs. Pouter Pigeon Breast

The name pectus carinatum comes from the Latin “chest keel,” referring to its similarity to the shape of the keel of ancient Roman ships.[1] For this reason, some people refer to pectus carinatum as keel chest. This condition is also known by the common name pigeon chest, which is derived from the fact that the protruding chest in some patients can appear similar to the shape of a bird’s breast.

The term pouter pigeon breast refers to a rare type of pectus carinatum where the uppermost part of the breastbone protrudes more than the rest of the chest (chondromanubrial prominence).[2] Specifically, it refers to the protrusion of the breastbone region known by the medical name “manubriosternal junction” or “angle of Louis,” as well as hardening (ossification) of this part of the breastbone. This gives the chest a unique shape reminiscent of the birds known as "poster pigeons." Pouter pigeon breast is the most severe form of pectus carinatum and can usually only be treated with surgery.[2] 

Another common name you may hear when discussing pectus carinatum is “chicken breast.” This refers to the more common type of pectus carinatum known scientifically as chondrogladiolar prominence, where the lower or middle parts of the chest protrude the most.[3,4] This type is much less severe than pouter pigeon chest, and surgery is not generally recommended as the first line of treatment. 

Pectus Carinatum Pigeon Breast Brace - Dakota Brace

In short, the colloquial names chicken breast and pouter pigeon breast refer to the same condition: namely, pectus carinatum. However, they refer to different classes of this condition, with pouter pigeon chest being much more severe. 

What Are the Signs of Pectus Carinatum?

The most obvious sign of pectus carinatum is chest protrusion. However, this is generally not evident in younger children, with less than one in every ten sufferers diagnosed before age 11.[4] Due to the rapid growth that occurs during puberty, including the growth of the breastbone, any minor protrusion becomes much more evident during this time.

However, a combination of early warning signs may indicate pectus carinatum, particularly in younger children. These can include: 

  • Excessive or continual fatigue
  • Shortness of breath 
  • Fast heart rate (tachycardia)
  • Chest pain
  • Poor posture, particularly hunched or hooked shoulders
  • Sideways or front-to-back curvature of the spine (scoliosis or kyphosis)

It is important to note that many of these are not specific to pectus carinatum in isolation and may result from other conditions. 

Pectus Carinatum Causes and Risk Factors

The exact causes of pectus carinatum are not yet fully understood. However, genetic inheritance appears to be responsible for at least 25% of cases.[5] The remaining variation is attributed to environmental factors and random chance.[6] Notably, pectus carinatum is 3–4 times more likely to occur in males than females.[6] In all cases, pectus carinatum is congenital (present at birth), even if it does not become evident until later in life. 

There are a number of conditions that commonly occur in conjunction with pectus carinatum. Although these do not cause pigeon chest, the presence of these conditions does increase the chance of also having pectus carinatum. These associated conditions include:

  • Trisomy 18 — Also known as Edwards syndrome, is a chromosomal condition where babies have an extra copy of chromosome 18. Individuals with this condition often have abnormalities in many organs. 
  • Trisomy 21 (Down syndrome) — Similar to trisomy 18, individuals with Down syndrome have an extra chromosome 21, which can cause developmental problems and intellectual disability. 
  • Homocystinuria — This inherited disorder results in an inability to correctly process the amino acid methionine, which can cause problems with nervous tissue, the vascular system, and muscle/connective tissue (including chest abnormalities). 
  • Marfan syndrome — This genetic disorder also causes abnormal growth of connective tissue, resulting in tall individuals with unusually long limbs and digits. 
  • Ehlers-Danlos syndrome — Another inherited disorder that primarily affects connective tissue. 
  • Noonan syndrome — Unlike many other disorders discussed here, Noonan syndrome generally results from mutations across at least eight different genes. It can cause a wide range of symptoms, most commonly including short stature, a broad neck, and chest deformity. 
  • Multiple lentigines syndrome — A subclass of Noonan syndrome which causes issues with the skin, head and face, inner ear, and heart. It is characterized by brown skin spots called lentigines. 
  • Morquio syndrome — Similar to homocystinuria, Morquio syndrome results from a genetic inability to break down certain sugars known as glycosaminoglycans. Accumulation of these compounds in the body slows development and produces skeletal abnormalities. 
  • Osteogenesis imperfecta — Often resulting from the improper formation of type I collagen, osteogenesis imperfecta causes individuals to have very fragile bones. Pectus deformities may be associated with this condition, albeit less commonly than the aforementioned disorders.

Associated Disorders

In addition to the aforementioned congenital conditions, a number of medical conditions can commonly be associated with pectus carinatum. These include:

  • Kyphosis — Outward curvature of the spine
  • Scoliosis — Sideways curvature of the spine
  • Heart disease
  • Mitral valve prolapse
  • Abnormal growth patterns

Diagnosis and Tests

Pectus carinatum is diagnosed by a doctor following careful examination of the chest. This may include taking X-rays of the chest which show the breastbone structure and any potential protrusion. In some cases, they may also use computed tomography (CT) or magnetic resonance imaging (MRI) scans. 

Genetic tests may be available to check for some of the associated conditions previously listed. However, they cannot be used to check for pectus carinatum specifically. 

Pigeon Breast Causes - Dakota Brace

How Dakota Brace Solutions Can Help You

The recommended first line of treatment for most pectus carinatum cases — particularly chicken breast (chondrogladiolar prominence) — is orthotic bracing.[7] This is where Dakota Brace can help. We provide custom-made, 3D-printed chest braces specifically designed to treat pectus carinatum. These are worn for up to 23 hours per day for an extended period (usually at least six months), so getting the perfect fit for your child is crucial. Over time, the pressure applied by the brace remodels the growth pattern of the breastbone cartilage, correcting the outgrowth.[8] 

Our team of certified clinicians draws on years of expertise to provide full support at every step of the process. Even better, everything can be done remotely* and around your schedule without compromising the quality of the final product.

*Note: You will need access to an iPhone X or later to do your initial scan. 

Wrap Up

Do you want to speak to a health professional about how to effectively treat your pectus carinatum? Ready to restore your health and confidence? Get a free consultation and get $75 off your first order, and get evaluated for either our Custom Pectus Brace (The Dakota Brace) or our Custom Pectus & Two Rib Flare Brace (The Bison Brace).


  1. Robicsek F, Watts LT. Pectus carinatum. Thorac Surg Clin. 2010;20:563–74.
  2. Fokin, A. A. (2000). Pouter pigeon breast. Chest surgery clinics of North America, 10(2), 377-391.
  3. Frey, A. S., Garcia, V. F., Brown, R. L., Inge, T. H., Ryckman, F. C., Cohen, A. P., ... & Azizkhan, R. G. (2006). Nonoperative management of pectus carinatum. Journal of Pediatric Surgery, 41(1), 40-45.
  4. Fonkalsrud, E. W. (2008). Surgical correction of pectus carinatum: lessons learned from 260 patients. Journal of Pediatric Surgery, 43(7), 1235-1243.
  5. Shamberger, R. C. (1996). Congenital chest wall deformities. Current Problems in Surgery, 33(6), 469-542.
  6. Cobben, J. M., Oostra, R. J., & van Dijk, F. S. (2014). Pectus excavatum and carinatum. European Journal of Medical Genetics, 57(8), 414-417.
  7. Emil, S. (2018). Current options for the treatment of pectus carinatum: When to brace and when to operate?. European Journal of Pediatric Surgery, 28(04), 347-354.
  8. Lee, R. T., Moorman, S., Schneider, M., & Sigalet, D. L. (2013). Bracing is an effective therapy for pectus carinatum: interim results. Journal of Pediatric Surgery, 48(1), 184-190.