Breathless and Coughing Pink Froth After a Dive: Immersion Pulmonary Edema Explained
Fluid can flood the lungs of a fit, healthy diver in cold or calm water alike. What immersion pulmonary edema is, who gets it and why mild symptoms should never be shrugged off.
Saturday, October 17, 2026/3 min read
The dive was routine. In a case summary published by Divers Alert Network, a man in his forties made an 11-metre shore dive in a 7 mm wetsuit, surfaced after 46 minutes on a controlled ascent, and a few minutes later began coughing and fighting for breath. Doctors ruled out decompression sickness. What he had was immersion pulmonary edema, or IPE, fluid in the lungs brought on by being in the water.
It is a condition most recreational divers have never been taught about, and one that can look like panic, low gas or the bends. It matters because the early symptoms are easy to explain away.
What is immersion pulmonary edema?
According to DAN, IPE, also called swimming-induced pulmonary edema, has been described in scuba divers, snorkellers, triathletes and military swimmers. The main features are shortness of breath, coughing, sometimes blood in the sputum and a feeling of wet lungs, often with extreme tiredness. Symptoms do not depend on depth and can occur with any immersion.
The theory is that immersion pushes blood from the limbs into the chest, raising the pressure in the blood vessels of the lungs, so that in a susceptible person fluid leaks into the air spaces. A 2022 case report by Geneva University Hospitals authors in the International Journal of Legal Medicine adds that dense gas and high breathing resistance increase the effort of breathing and the strain on those vessels.
Who gets it, and how often?
DAN lists cold water, over-hydration, uncontrolled high blood pressure, heavy exertion and high breathing resistance, especially on inhalation, as contributors. Not every factor needs to be present, and IPE has occurred in warm water. DAN says susceptibility cannot currently be predicted. The Geneva authors add emotional stress and a tight thigh-length wetsuit to the list, and say that it can strike generally healthy people and is seen more often in men over 50.
They estimate IPE at about 1.1 percent of diving accidents, call it largely underdiagnosed, and put the chance of it happening again at roughly 30 percent. They also say it can cause incapacitation in the water, which is why it complicates the interpretation of some fatal dives.
What are the warning signs?
DAN's guide to lung conditions lists chest pain, shortness of breath, wheezing and pink, frothy sputum, either underwater or soon after surfacing. The Geneva paper says symptoms usually start within about ten minutes of immersion and tend to worsen on the way up. The same symptoms can come from a lung overexpansion injury or a clot, which is why DAN says the answer is medical assessment rather than self-diagnosis.
What should a diver do about it?
DAN advises that a diver with symptoms leave the water as soon as it is safe, tell the buddy, make a controlled ascent finishing any required decompression, limit exertion, take oxygen and get a medical evaluation. In its case summary the diver was treated in hospital, kept overnight and went home with his lungs feeling raw for about 24 hours. The Geneva authors recommend rewarming, oxygen, and a hospital stay of two to three days followed by about a month away from diving, and say hyperbaric oxygen is only for cases that also involve decompression sickness. Those are clinical recommendations from a case report, and any return to diving is a decision for a physician, ideally one trained in diving medicine.
Prevention, per DAN, means addressing the risk factors: not overhydrating before a dive, avoiding overexertion, and getting blood pressure and weight under medical review. A pre-dive check with a doctor also matters, as we explained in our guide to the diving medical form.
The practical lesson is small and unglamorous. Mild breathlessness that does not fade, or a cough that arrives after a perfectly ordinary dive, is a reason to tell someone and to get checked. This is journalism, not instruction; training and medical clearance belong with a certified instructor, an agency and a physician.
Published in The Outspoken Digest
Editorial desk
Outspoken Digest Diving DeskCovers freediving, recreational and technical diving, dive medicine and the incidents the sport learns from.
Newsletter
The Digest, in your inbox
One edition, sent when it is ready. No noise, and your address is never passed on.
Read Next
More Diving →
Your Gas Consumption Is Not One Number: Why Depth, Cold and Nerves Change It
Oct 16, 2026/3 min read
SS United States Reef Sinking Targeted for November: What Divers Should Know
Oct 16, 2026/2 min read
Divers Excavating Off Kekova Find a Wreck Believed to Be the World's Oldest, Turkey Says
Oct 15, 2026/2 min read
Bleached Corals Recovered After Touching a Healthy Clone, Stanford Lab Study Finds
Oct 15, 2026/2 min read