Skip to Content

Immersion Pulmonary Edema

(Swimming-Induced Pulmonary Edema; SIPE)


Richard E. Moon

, MD, Duke University Medical Center

Last full review/revision Jun 2021| Content last modified Jun 2021

Immersion pulmonary edema is sudden development of fluid in the lungs that typically occurs early during a dive and at depth.

(See also Overview of Diving Injuries.)

Immersion pulmonary edema has become more widely recognized over the past two decades. It happens when blood from the legs and abdomen is redistributed to the lungs, which increases pressure in the blood vessels of the lungs, causing leakage of plasma into the air spaces. This usually occurs in competitive open-water swimmers at the surface but can also occur in divers. Immersion pulmonary edema is not related to lung barotrauma or decompression sickness. Cold water and a history of high blood pressure and other cardiovascular disorders are risk factors.

Divers usually ascend rapidly and become very short of breath. A cough with frothy or bloody sputum is typical and blood oxygen levels are low.

Doctors may do tests such as chest x-rays and echocardiography to confirm the diagnosis.

Treatment includes removal from the water and oxygen. Diuretics and mechanical ventilation in the hospital are sometimes necessary. Recompression therapy is not given.


Doctors will screen people who have had immersion pulmonary edema for

Doctors will also consider silent coronary artery disease in people with appropriate risk factors.

Immersion pulmonary edema tends to recur in susceptible individuals; therefore, such people should be evaluated for treatable risk factors before returning to diving or competitive swimming.

More Information

The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.

  • Divers Alert Network: 24-hour emergency hotline, 919-684-9111
  • Duke Dive Medicine: 24-hour emergency consultation with a doctor, 919-684-8111

Copyright © 2022 Merck & Co., Inc., known as MSD outside of the US, Kenilworth, New Jersey, USA. All rights reserved. Merck Manual Disclaimer