Sports-Related Lung Injury During Breath-Hold Diving
Authors: Tanja Mijacika, Zeljko Dujic
DOI / Source: 10.1183/16000617.0052-2016
Date: 2016
Reading level: Intermediate
Why This Matters for Freedivers
A lot of lung issues in freediving start as “just a cough” or “a bit tight,” but they can actually be signs of real lung stress (fluid leak, tiny bleeding, or pressure injury). This review gives you a clear map of what these injuries are, why they happen, what increases risk, and which symptoms should make you stop and take it seriously.
Synopsis
This review is basically a practical “field guide” to lung problems that can happen in breath-hold diving—especially after repetitive sessions or deep dives. The authors start with an important reality check: as freediving grows, more people are pushing the lungs into unusual combinations of stress—pressure, low oxygen, high CO₂, cold water, and sometimes hard swimming. Even if you’re fit, the lungs are built for thin, delicate gas exchange, and that thin barrier can be stressed by diving in ways that don’t happen in most sports.
A key takeaway is how common mild symptoms are. The review notes that around a quarter of breath-hold divers report respiratory symptoms after repetitive diving sessions—things like cough, chest tightness, or shortness of breath. Many divers shrug these off. But the review explains why those symptoms can reflect real physiology: repeated dives can raise transpulmonary capillary pressure (pressure across the tiny lung blood vessels) enough to cause stress failure of the blood–gas barrier. When that happens, fluid can leak into the air spaces (non-cardiogenic pulmonary edema), and in more severe cases there can be alveolar hemorrhage (coughing blood).
The paper breaks lung injury in freediving into two big buckets:
1) Pulmonary barotrauma (pressure injury from volume change).
As you descend, your lungs compress. Past a certain point, further compression can’t happen easily, and the pressures inside the chest become strongly negative. That can contribute to “lung squeeze” and atelectasis (collapse of parts of the lung). On ascent, the opposite risk appears: lung volume expands. If you don’t exhale appropriately (or if you ascend with poor technique), overexpansion can damage alveoli and airways and lead to air leaks (pneumomediastinum, pneumothorax, etc.). In the worst case, air can enter the bloodstream and cause arterial gas embolism, which is a true emergency.
2) Edema and bleeding (capillary stress + pressure swings).
The review explains that immersion shifts blood toward the chest, cold water tightens blood vessels, and the diving response changes circulation—together raising pressures inside the pulmonary circulation. Add hard effort and you can push the capillaries even harder. There’s also a freediving-specific twist: during the “struggle phase,” involuntary breathing movements against a closed glottis can create strong negative pressure swings, which can further increase venous return and pulmonary blood volume—again pushing capillary pressures toward a “leak” scenario.
The paper also talks about lung packing (glossopharyngeal insufflation): it can increase oxygen stores and allow deeper dives, but it also creates unusually high pressures and can stress both lung tissue and circulation, plus it can reduce venous return and blood pressure (rarely even causing fainting). The message isn’t “never pack,” but rather “this is a powerful tool with real physiological costs.”
Finally, the review addresses the big question: does freediving cause long-term lung damage. Based on available evidence, the authors say there’s no strong evidence for chronic lung injury from breath-holding itself, but they also point out that long-term data (especially in very deep divers and large populations) is limited. The safest conclusion is: most lung stress seems transient and reversible, but repeated injury and individual susceptibility still matter—so prevention, conservative progression, and symptom awareness are key.
Abstract
The number of people practising recreational breath-hold diving is constantly growing, thereby increasing the need for knowledge of the acute and chronic effects such a sport could have on the health of participants. Breath-hold diving is potentially dangerous, mainly because of associated extreme environmental factors such as increased hydrostatic pressure, hypoxia, hypercapnia, hypothermia and strenuous exercise.
In this article we focus on the effects of breath-hold diving on pulmonary function. Respiratory symptoms have been reported in almost 25% of breath-hold divers after repetitive diving sessions. Acutely, repetitive breath-hold diving may result in increased transpulmonary capillary pressure, leading to noncardiogenic oedema and/or alveolar haemorrhage. Furthermore, during a breath-hold dive, the chest and lungs are compressed by the increasing pressure of water. Rapid changes in lung air volume during descent or ascent can result in a lung injury known as pulmonary barotrauma. Factors that may influence individual susceptibility to breath-hold diving-induced lung injury range from underlying pulmonary or cardiac dysfunction to genetic predisposition. According to the available data, breath-holding does not result in chronic lung injury. However, studies of large populations of breath-hold divers are necessary to firmly exclude long-term lung damage.