Most cases of pectus excavatum are mild and pose no medical danger. But in moderate to severe cases, the inward dip of the breastbone can compress the heart and lungs enough to cause real, measurable problems with breathing and exercise tolerance. About 1 in 300 to 1 in 1,000 people are born with the condition, making it the most common chest wall deformity, and it’s five times more common in males.
Whether your case is “serious” depends on how deep the depression is, whether it’s affecting your heart or lung function, and how it impacts your daily life. Here’s how to think through each of those factors.
How Severity Is Measured
Doctors use a measurement called the Haller index to grade how severe pectus excavatum is. It’s a ratio calculated from a cross-sectional image of your chest: the width of your ribcage divided by the distance between your spine and the deepest point of your breastbone. A normal chest has an index around 2.5. An index of 3.25 or higher is considered significant, and the higher the number, the more severe the condition.
This measurement has traditionally been taken with a CT scan, but many centers now use a fast MRI technique instead. MRI produces equally reliable measurements without exposing you to radiation, which is especially relevant for younger patients who may need repeat imaging over time.
What Happens to the Heart
In moderate to severe cases, the depressed breastbone physically pushes on the heart, particularly the right ventricle (the chamber that pumps blood to the lungs). This external compression can interfere with how well the heart fills with blood and how effectively it pumps.
Research on pediatric patients found that about 19% had reduced pumping function in the right ventricle, and patients with a Haller index above 3.25 had slightly lower right ventricle performance. One telling study compared exercise capacity in patients versus healthy controls: when exercising in a seated or upright position, patients pumped significantly less blood per heartbeat (55 mL versus 65 mL in controls) and had lower peak oxygen uptake. But when the same patients exercised lying down, their heart function nearly matched the control group. The explanation is straightforward: in the upright position, gravity already makes it harder for blood to fill the heart. Add a breastbone pressing on the heart, and filling drops even further.
This is why many people with pectus excavatum feel fine at rest but notice shortness of breath, a racing heart, or early fatigue during sports or physical activity.
What Happens to the Lungs
A deep chest depression also reduces the space available for your lungs to expand, creating what’s called a restrictive pattern on breathing tests. In a large study of over 1,500 surgical patients with severe pectus excavatum, lung function values were shifted significantly lower than expected. One study of 152 patients (average age 15) found that their measured vital capacity, the total amount of air they could exhale after a full breath, was only 78% of what would be predicted for their age and size. A smaller study from Switzerland found even more dramatic restriction, with vital capacity at roughly 64% of predicted values before surgery.
The deeper the depression, the worse the restriction tends to be. Patients with a Haller index greater than 7 were four times more likely to show a restrictive breathing pattern than those with a lower index. For many people with mild pectus, lung function tests come back normal or near-normal.
The Psychological Side
Even when pectus excavatum doesn’t cause significant heart or lung problems, the psychological burden can be substantial, particularly for adolescents. Studies have found that 62.5% of patients with pectus excavatum report feeling shame about their chest, and 40% are constantly preoccupied with it. Social anxiety scores are notably elevated: 43% of patients in one study had scores suggesting a possible social anxiety disorder.
Between 44% and 57% of adolescents with the condition intentionally hide it, layering clothing, folding arms across their chest, or avoiding swimming and athletics where their chest might be visible. School functioning was impaired in 42% of individuals in one study, and social functioning in 26%. More than 60% of patients reported suffering from teasing by peers. These psychological effects are not trivial. Body image scores in patients with chest wall deformities are consistently lower than in healthy controls, and the degree of distress correlates strongly with overall quality of life.
Does It Get Worse Over Time?
Pectus excavatum is present from birth, but the depression often deepens during the growth spurts of early puberty. In some people, it continues to progress into adulthood. If the condition is severe, it can gradually worsen heart and lung function over the years. People may notice a slow decline in exercise tolerance, increasing shortness of breath, or chest pain and pressure that wasn’t there before. Mild cases, by contrast, often remain stable and cause no progressive symptoms.
When Surgery Becomes the Right Option
Surgery is typically considered when the Haller index exceeds 3.25 and at least one of the following is present: breathing tests show moderately severe restriction, an echocardiogram shows the heart is being compressed, exercise testing reveals cardiovascular or breathing limitations, or the deformity is getting worse with associated physical symptoms. The most common procedure (the Nuss procedure) involves placing a curved metal bar behind the breastbone to push it outward, which stays in place for a few years before removal.
Results are generally good. In a multicenter study of 327 patients from 11 North American centers, lung capacity improved from about 88% to 93% of predicted values after surgery, and total lung capacity went from 94% to essentially 100% of predicted. The Swiss study found even larger improvements: vital capacity and air flow both improved by roughly 38% to 40% after repair.
Non-Surgical Options for Younger Patients
For milder cases, or for families who want to avoid surgery, a device called a vacuum bell offers a non-surgical alternative. It’s a suction cup placed over the chest that gradually lifts the breastbone over months of daily use. In a retrospective study of 72 patients, about 25% achieved excellent correction and another 18% achieved good correction based on Haller index improvement. The strongest predictors of success were starting before age 11 (nearly four times the odds of a meaningful result) and using the device consistently for more than 24 consecutive months (nearly seven times the odds). Patients who started after age 11 had significantly less improvement.
This means the vacuum bell works best as an early intervention for children with mild to moderate cases. For older teens and adults, or for severe deformities, surgery remains the more reliable path to correction.