Stephen J. Schueler, M.D.

Overview Incidence Risk Factors Symptoms Evaluation Treatment Home Care decongestants pain control warning signs Prevention Underlying Cause Types ascent injury pneumothorax reverse squeeze descent injury

Underwater Diving Injuries Types

Pressure on the body increases as a diver descends deeper into the water. The body may be unable to equalize the pressure between the water and the pressure inside a cavity, such as the middle ear, sinuses or lungs. An injury related to the increasing pressure is called squeeze, or a descent scuba injury.

Types of squeeze injuries include:


Pressure on the body decreases as a diver ascends to the surface. As the pressure decreases, trapped air expands. The expanding air can cause serious injury to a body cavity. An injury related to the decreasing pressure is called reverse squeeze, or an ascent scuba injury.

Types of reverse squeeze injuries include:

Underwater Diving Injuries Ascent Injury

Air is present at atmospheric pressure in many areas of the body. Hollow areas such as the ears, sinuses, intestines and others are directly affected by outside air pressure.

The pressure applied to the body decreases greatly as a person ascends closer and closer to the surface. The body may be unable to equalize the pressure between the water and the pressure inside a cavity, such as the middle ear, sinuses or lungs. As the pressure decreases, trapped air expands in the air cavities.

Less serious injuries include:


The expanding air can cause serious injury to a body cavity. The diving term for this is called a pop.

More serious injuries include:

Underwater Diving Injuries Pneumothorax

A pneumothorax is a collapsed lung. A pneumothorax can occur in a diver who fails to exhale completely during ascent.

The sequence of events includes:

  • Gas expands in the lungs as the surrounding pressure decreases during ascent.
  • The lung becomes over-inflated.
  • The small air sacs in the lung rupture.

When air escapes outside the lungs, the air collects in the space between the outside of the lung and the inside the chest cavity.

Underwater Diving Injuries Reverse Squeeze

Reverse squeeze occurs when gas expands in the ear, sinuses or intestines as the surrounding pressure decreases during ascent.

Reverse ear squeeze
In this case, air expands in the middle ear, causing pain. The eardrum can rupture if the pressure increases too much.

Tooth reverse squeeze
Fillings, decay, dental infections, or recent extractions can form tiny pockets of air around a tooth. Severe dental pain occurs when the pressure increases inside the air pocket.

Sinus reverse squeeze
In this case, air expands in the sinuses, causing pain. The wall of the sinus can rupture if the pressure increases too much.

Intestinal reverse squeeze
This is caused by the expansion of gas in the intestine when the surrounding pressure is decreased during ascent.

Underwater Diving Injuries Descent Injury

The pressure applied to the body increases greatly as a person descends deeper and deeper in the water. Squeeze occurs when pressure from the surrounding water compresses gas in the ear, sinuses, or intestines, as the pressure increases during descent.

Barotitis externa
In the case, pressure is exerted on the ear canal when a diver descends. A small pocket of air in the ear canal can form if the ear canal is plugged with wax or earplugs. This can result in eardrum rupture or damage to the ear canal.

Barotitis media
In this case, pressure is exerted on the middle ear. This can also result in eardrum rupture.

Last Updated: Jan 4, 2011 References
Authors: Stephen J. Schueler, MD; John H. Beckett, MD; D. Scott Gettings, MD
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