What is an abnormal chest formation?

October 2, 2025 •

4 min read

According to the National Institutes of Health, pectus excavatum, or sunken chest, is the most common congenital chest wall abnormality. An abnormal chest formation, also known as a chest wall deformity, is a structural irregularity of the ribs, sternum (breastbone), or cartilage.

Quick Summary

An abnormal chest formation is a congenital or developmental irregularity of the chest wall, most commonly presenting as a caved-in (pectus excavatum) or protruding (pectus carinatum) sternum, which can range from mild to severe, and may affect cardiopulmonary function or self-esteem.

Key Points

Understanding an Abnormal Chest Formation: Also known as a chest wall deformity, it's a structural irregularity of the chest, often involving the sternum and rib cage.
Pectus Excavatum (Sunken Chest): The most common type, causing the breastbone to push inward and create a caved-in appearance.
Pectus Carinatum (Protruding Chest): The second most common type, where the breastbone and ribs protrude outward, sometimes called 'pigeon chest'.
Diagnosis is Key: Imaging tests like X-rays or CT scans are used to assess the severity, and heart and lung function may be evaluated with echocardiograms or pulmonary tests.
Treatment Varies by Severity: Options range from observation for mild cases to non-surgical methods like bracing and vacuum bells, or surgical correction for more severe conditions.
Psychosocial Impact: Regardless of physical symptoms, the cosmetic aspect can affect self-esteem, making psychological counseling an important part of care.

Common Types of Abnormal Chest Formations

Abnormal chest formations, clinically known as chest wall deformities, encompass a variety of conditions affecting the skeletal structure of the chest. While many cases are mild and purely cosmetic, more severe forms can impact the function of the heart and lungs. These conditions can be congenital, present at birth, or develop during childhood, often becoming more pronounced during adolescent growth spurts.

Pectus Excavatum (Sunken or Funnel Chest)

Pectus excavatum is the most prevalent chest wall deformity and is characterized by a sunken or caved-in appearance of the sternum. This occurs due to an overgrowth of the cartilage connecting the ribs to the breastbone, which pushes the sternum inward. The severity can range from a shallow dip to a deep, asymmetrical depression. While many individuals with mild cases have no symptoms, those with more severe indentations may experience a variety of issues:

Shortness of breath, especially during exercise
Fatigue
Chest pain or discomfort
Heart palpitations, fluttering, or a rapid heartbeat
Poor posture, such as rounded shoulders

Pectus Carinatum (Pigeon or Protruding Chest)

In contrast to pectus excavatum, pectus carinatum causes the chest to push outward. This deformity is caused by an overgrowth of the costal cartilage that forces the breastbone forward. It is less common than pectus excavatum and, like its counterpart, can vary in severity. Symptoms are often less pronounced than with a sunken chest, but can include:

Exercise-induced asthma or breathing difficulty
Chest wall pain or tenderness
Self-consciousness about appearance

Other, Rarer Deformities

Beyond the two most common types, other, less frequent abnormal chest formations exist. These may involve the ribs, sternum, or associated muscles and soft tissues. Examples include:

Pectus Arcuatum: A variant of pectus carinatum where the deformity results from premature fusion of sternal sutures.
Poland Syndrome: A rare condition characterized by the underdevelopment or absence of the chest muscle on one side, which may be accompanied by underdeveloped breast tissue, ribs, or an arm on the same side.
Jeune Syndrome (Asphyxiating Thoracic Dystrophy): A genetic disorder resulting in a narrow chest cavity that can severely restrict lung growth and breathing capacity.

Diagnosis and Evaluation

Diagnosing an abnormal chest formation typically involves a physical examination by a healthcare provider. During the exam, the doctor will assess the shape and severity of the deformity. To gain a clearer picture and determine the best course of action, additional diagnostic tests may be ordered.

Imaging Tests: X-rays or CT scans can be used to visualize the chest structure and measure the severity of the indentation or protrusion. For pectus excavatum, the Haller index, a ratio derived from a CT scan, is often used to quantify severity.
Cardiac Evaluation: An echocardiogram, or ultrasound of the heart, can assess the heart's position and function, especially in severe pectus excavatum where the sternum may be compressing the heart.
Pulmonary Function Tests: These tests measure lung capacity and function to see if the chest deformity is restricting breathing.

Treatment Options

Treatment for chest wall deformities depends on the type, severity, and whether the condition is causing physical or psychological symptoms. For many mild cases, no treatment is necessary beyond monitoring during childhood growth periods.

For more severe or symptomatic cases, a variety of options are available:

Bracing (Non-surgical): For pectus carinatum, custom-made braces can apply pressure to the protruding area to gradually reshape the chest wall. This is most effective during periods of rapid growth. A vacuum bell device may be used for mild pectus excavatum to create a suction that pulls the sternum forward over time.
Minimally Invasive Surgery (Nuss Procedure): Primarily used for pectus excavatum, this procedure involves inserting a curved metal bar beneath the breastbone to push it into a normal position. The bar is typically removed after several years.
Open Surgery (Modified Ravitch Technique): Involves a larger incision to remove the excess cartilage and reshape the chest wall. This may be used for more complex cases or for pectus carinatum.

Long-Term Outlook and Management

For most individuals, particularly those with mild abnormalities, an abnormal chest formation does not lead to significant health problems. The psychosocial impact, such as self-esteem issues and body image concerns, can be a major factor for some, regardless of physical symptoms. Addressing these concerns with psychological counseling or support groups can be beneficial.

For those undergoing treatment, the prognosis is generally excellent. Early intervention, especially during adolescence when the chest wall is more pliable, can lead to very successful outcomes. Close monitoring and follow-up care are important to ensure proper development and address any potential complications. It is crucial to consult with a specialist, such as a pediatric or thoracic surgeon, to determine the most appropriate and effective treatment plan for your specific situation. For comprehensive information on various conditions and treatments, the Mayo Clinic is an excellent resource: Mayo Clinic Pectus Excavatum.

Comparison of Common Chest Deformities


Feature	Pectus Excavatum	Pectus Carinatum
Appearance	Sunken or caved-in sternum	Protruding or pushed-out sternum
Cause	Overgrowth of costal cartilage pushing the sternum inward	Overgrowth of costal cartilage pushing the sternum outward
Commonality	Most common chest wall deformity	Second most common chest wall deformity
Associated Conditions	Marfan syndrome, scoliosis, Ehlers-Danlos syndrome	Marfan syndrome, scoliosis, connective tissue disorders
Potential Symptoms	Shortness of breath, fatigue, chest pain, palpitations	Exercise-induced asthma, chest wall pain, psychosocial distress
Primary Treatment	Non-invasive (vacuum bell) or surgical (Nuss procedure, Ravitch)	Non-invasive (bracing) or surgical (open procedures)

Frequently Asked Questions

An abnormal chest formation is medically referred to as a chest wall deformity. Common types have specific names, such as pectus excavatum for a sunken chest and pectus carinatum for a protruding chest.

Pectus excavatum is relatively common, occurring in about 1 in 300 to 400 children. Pectus carinatum is less common, affecting approximately 1 in 1,500 children.

The exact cause is often unknown, but it is typically linked to an uneven or excessive growth of the cartilage that connects the ribs to the sternum. Genetics may also play a role, as the condition sometimes runs in families.

In moderate to severe cases of pectus excavatum, the inward-pushing sternum can compress the heart and lungs, potentially causing shortness of breath, especially during physical activity.

No, surgery is not always necessary. Mild cases may require no treatment at all, and non-surgical methods like external bracing for pectus carinatum or vacuum bells for pectus excavatum are often effective, especially in younger patients.

For deformities that worsen with growth, such as pectus carinatum, bracing is most effective during adolescent growth spurts. Surgical repairs are often performed during the late teenage years, but this depends on the individual case.

They often become more noticeable and may worsen during adolescent growth spurts. In most cases, once a person finishes growing, the deformity will likely not change.