Swimming Induced Pulmonary Oedema

dxaugustine
Mar 17
2 min read

Updated: May 6

Dan Augustine was senior author for this recently published research, featured in The Guardian and published in the British Medical Journal: Case Reports

Swimming is often celebrated for its health benefits, but beneath the surface lies a lesser-known risk that even the fittest swimmers may face. Swimming-Induced Pulmonary Oedema (SIPE) is a potentially serious condition that can cause sudden breathlessness, coughing up pink, frothy sputum, and dangerously low oxygen levels -sometimes with fatal consequences.

What Is Swimming-Induced Pulmonary Oedema (SIPE)?

Unlike drowning, where water enters the lungs from the outside, SIPE involves fluid accumulating within the lungs from the body’s own response to exertion, immersion, and cold water. It can strike suddenly and without warning, leaving swimmers gasping for air mid-swim.

Experts warn SIPE may be more common than previously thought. Dr Peter Wilmshurst, a leading cardiologist who first described the condition, believes some unexplained swimming deaths may in fact be due to SIPE. Statistics show around 1 in 200 participants in Sweden’s Vansbro Swim develop SIPE, while it has been documented in 1 in 20 Navy SEAL recruits.

A Case That Raises Questions

One notable case involved a healthy woman in her 50s who experienced SIPE during a night swim in water at 17°C. After exiting the water and removing her wetsuit, she felt a sudden sensation of her lungs filling with fluid and began coughing up pink froth. She was treated promptly and recovered within 24 hours, but medical scans revealed unexpected fluid around her heart.

Was this heart involvement an underlying condition - or a direct result of the SIPE episode? The answer remains unclear, but the finding opens new avenues for understanding how the heart and lungs respond under these conditions.

What Swimmers Should Know about SIPE

While SIPE is rare, certain factors - including age, high blood pressure, swimming in cold water, and female sex - may increase risk. Medical experts recommend caution: if you experience unusual breathlessness while swimming, exit the water immediately and seek medical attention.

The condition’s causes, frequency, and long-term implications are still being investigated. Could SIPE explain more unexplained incidents in open water than we realise? And how should swimmers adjust their practices in response?