Pectus excavatum explained

Pectus excavatum — sometimes called sunken or funnel chest — is a chest wall difference where the sternum sits deeper than the surrounding ribs. This guide covers what is known about it, how depth is assessed, and how self-tracking fits in.

Why the chest sinks inward

The current consensus is that the cartilage connecting the ribs to the sternum grows faster than the bone around it. That extra length has to go somewhere, and it pushes the sternum backwards. Depth commonly increases during the adolescent growth spurt and then stabilises in early adulthood, which is why treatment discussions often happen in the teenage years.

How severity is measured

• Haller index — the width of the chest divided by the distance between the sternum and the spine on a CT or MRI slice. Above roughly 3.25 is often described as significant.
• Correction index — how much of the chest depth is "missing" as a percentage, less sensitive to chest shape than the Haller index.
• External depth — the practical at-home measure: place a straight edge across the chest and measure straight down to the deepest point, in centimetres or inches.

Measuring consistently at home

Home measurements are only useful if the technique never changes. Measure at the same time of day (mornings, before treatment), in the same body position, at the end of a relaxed exhale, and always to the same anatomical point. Day-to-day variation of a couple of millimetres is normal — hydration, posture and breathing all move the number. Judge progress on the trend over weeks, not on any single reading.

Symptoms people report

Many people have no physical symptoms at all. When symptoms occur they tend to be reduced exercise tolerance, breathlessness on exertion, chest discomfort or palpitations — the deep sternum can crowd the heart and lungs. Psychological impact, especially around body image in swimming or changing rooms, is well documented and is a valid reason to seek help.

Treatment options

• Observation — for mild, symptom-free cases, often combined with posture and back/chest strengthening work.
• Vacuum bell therapy — a suction cup that lifts the sternum over months of daily use. Best suited to flexible chests, typically in younger users. Read the vacuum bell guide.
• Nuss procedure — a minimally invasive operation placing a curved metal bar behind the sternum for two to three years.
• Ravitch repair — an open operation removing the abnormal cartilage and repositioning the sternum, used in complex or asymmetric cases.

Noticed the lower ribs sticking outward too? Read the flared ribs guide.

Common questions

What is pectus excavatum?

Pectus excavatum is the most common chest wall difference, where the breastbone and some rib cartilage grow inward, creating a sunken or 'funnel' chest. It affects roughly 1 in 300–400 people and is several times more common in males.

What causes it?

The exact cause is unknown. Most researchers point to overgrowth of the costal cartilage that connects the ribs to the sternum, which pushes the sternum backwards. It often runs in families and is more common in people with connective tissue conditions such as Marfan or Ehlers-Danlos syndrome.

How is severity measured?

Clinically, severity is usually described with the Haller index or correction index from a CT or MRI scan. At home, most people track external depth: the vertical distance from a straight edge laid across the chest down to the deepest point of the dip.

What symptoms can it cause?

Many people have no physical symptoms. Others report reduced exercise tolerance, shortness of breath on exertion, chest discomfort or palpitations. Body image and confidence effects are common and are a legitimate reason to seek care.

What are the treatment options?

Options range from observation and posture/strength work, to vacuum bell therapy, to surgery (the minimally invasive Nuss procedure or the open Ravitch repair). Which is appropriate depends on severity, symptoms, age and chest wall flexibility — a specialist assessment is essential.