Recognizing Lung Conditions

Acute lung conditions are some of the most dramatic and life threatening injuries found in the diving environment, and it is vital for all divers to be able to quickly recognize and react to them. Acute pulmonary condition can have long-lasting and serious effects, and requires prompt care. Here are some of the most common lung conditions faced by divers:

Pulmonary Overinflation Syndrome

This condition is typically the result of expansion of air during ascent either trapped in a segment of the lungs, or breath hold during ascent, and overinflation of both lungs. This overinflation can result in a lung barotrauma, which may manifest in a pneumothorax, mediastinal emphysema, or an arterial gas embolism. Lung expansion injuries can be prevented by ensuring that you and your dive buddies are medically fit to dive, remembering never to hold your breath, and by avoiding rapid ascents.


Symptoms of pulmonary overinflation syndrome include cough, hemoptysis (coughing up blood), chest pain, pink frothy sputum, vocal changes, discomfort swallowing, a feeling of fullness in the throat, difficulty breathing, as well as additional symptoms of subcutaneous or mediastinal emphysema, arterial gas embolism, and pneumothorax.

Immersion Pulmonary Edema (IPE)

Immersion pulmonary edema is one of several lung conditions that could affect you or your buddy during a dive. Common symptoms of IPE are chest pain, frothy pink sputum, and dyspnea, in divers who are or were recently submerged.

A form of pulmonary edema, an IPE is an accumulation of fluid in the lungs caused in part by immersion in water. IPE occurs because the opposing pressures of fluid surrounding the lungs are forced out of equilibrium, and excess fluid is allowed to build up in the pulmonary tissues. Immersion in water can increase the fluid pressure in the capillaries surrounding the lungs, and this pressure differential can be exacerbated by a number of risk factors, leading to an increased risk of edema. You can minimize your risk of IPE by addressing common risk factors like overhydration, overexertion, and hypertension, as well as obesity.


Symptoms of IPE include chest pain; dyspnea (discomfort or difficulty breathing); wheezing; and pink, frothy sputum while submerged or shortly after emerging from the water.

Pulmonary Embolism (PE)

A pulmonary embolism is another dangerous pulmonary condition which can occur unrelated to diving but may mimic dive injuries. It involves the blockage of blood flow in the vasculature of the pulmonary system by, fat, or blood clots. Common symptoms of a pulmonary embolism are chest pain, distension of the neck veins, and an altered level of consciousness, or fainting. If a diver shows any of these symptoms, PE should be one of the primary considerations, and immediate medical attention should be sought.


Symptoms of PE include chest pain (also known as “dyspnea”), pain or swelling of the calf (signaling a DVT), hypotension (abnormally low blood pressure), an altered level of consciousness and syncope (fainting). Distension of the neck veins in the absence of other conditions — such as pneumothorax (a buildup of air in the membrane surrounding the lungs, sometimes referred to as a collapsed lung) or heart failure — may also be observed in individuals suffering a PE.

For more information on lung health and diving, review the Pulmonary and Venous Disorders, chapter 6 in DAN’s Heart & Diving Dive Medical Reference Book.

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