Symptoms and Signs of Decompression Illness

Medical Author:
Medically Reviewed on 10/6/2021

Doctor's Notes on Decompression Illness

Decompression illness (also called caisson disease) is a condition that results when sudden decompression causes nitrogen bubbles to form in the tissues of the body. It occurs mainly in scuba divers (who often call it the bends). Two types of decompression illness may occur; type I involves muscles, skin, and lymphatics while type II involves the brain, ear, and lungs and is more serious. The symptoms begin about 6-48 hours after scuba diving; type I symptoms and signs include

  • muscle aches,
  • joint aches (usually elbows and shoulders), and
  • skin itch with a rash.

Type II symptoms and signs include

Less commonly, coughing, ringing in the ears and/or hearing loss, difficulties with urine and bowel control, blood in the stools, and shortness of breath can occur. Severe decompression symptoms include paralysis, slurred speech, vision loss, seizures, coma, and death.

Decompression illness is caused by gas bubbles becoming entrapped in the body when a diver rapidly ascends to the surface. Slow ascents and decompression stops (pausing your ascent at certain depths) allow the gas to disperse and decreases the chances to build up gas pockets. Inadequate exhalation during ascent, holding your breath while diving or air trapping due to water inhalation or underlying lung disease can contribute to gas formation, gas entrapment, and ultimately, decompression illness.

What Are the Treatments for Decompression Illness?

Treatment of decompression sickness is considered a medical emergency by many doctors. After diagnosis and placement on 100% oxygen, a chest X-ray is performed to rule out a pulmonary embolism (if it is present, HBO [hyperbaric oxygen] therapy is contraindicated). HBO therapy (recompression in a sealed chamber to reduce or stop bubble formation in tissues) is the preferred treatment for decompression sickness unless the patient first needs circulation, airway, and/or breaching stabilization. HBO treatments are not available at many hospitals; if the patient needs air transport, it should be on a pressurized aircraft or if by helicopter, not to go above 1,000 feet if possible. Any symptoms of decompression illness should be treated by HBO, even if seen several days after development.


Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.