Dr. Daniel Noltkamper, Medical Corps, United States Navy, received his undergraduate degree from the United States Naval Academy. He attended medical school at the University of Texas Medical Branch at Galveston, graduating in 1990. He completed his internship in Family Medicine at Naval Hospital Charleston. CDR Noltkamper served as a General Medical Officer and Radiation Health Officer on board the USS Bainbridge and Squadron Medical Officer at Regional Support Group Norfolk.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Decompression sickness is caused by the elevated pressures of the gas mixture
inhaled underwater that diffuse into the body tissues, and then the inadequate diffusion of the gas from
the tissues if the diver surfaces too quickly.
Middle ear squeezes occur because of obstruction of the Eustachian tube.
The most common cause is an upper respiratory infection (cold), creating congestion.
Other causes of obstruction include congestion caused by
smoking, mucosal polyps, excessively aggressive Valsalva attempts, or previous facial injuries.
Factors that trigger sinus squeezes include a cold,
sinusitis, or nasal polyps.
Contributing factors to aerogastralgia (swallowing air) include performing Valsalva maneuvers with
the head down (which allows air swallowing), consuming carbonated beverages or heavy meals prior to diving, or chewing gum while diving.
Pulmonary barotrauma occurs from the diver holding their breath during ascent, which allows pressure to rise in
The pressure increase results in rupture.
Air also may penetrate into the tissue around the lungs.
The classic description of a dive causing an air embolism is rapidly ascending to the surface because of panic.
Failure to make recommended decompression stops during ascent usually causes decompression sickness. Stops are based on diving tables or charts, which factor into account the depth, duration of the dive, and previous dives completed and give you guidelines on the proper rate of ascent.