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Typical signs and symptoms of decompression sickness are..
  • A
    high blood pressure, the chokes, and depression.
  • B
    tingling, dry cough, the bends, and dizziness.
  • C
    disturbance of consciousness, feeling cold, and depression.
  • D
    low blood pressure, the chokes, and high temperature.


Decompression sickness (DCS) is a condition caused by a rapid reduction in the ambient pressure surrounding the body. When decompression occurs, nitrogen and other inert gases that are normally dissolved in body tissue and fluid expand to form bubbles that rise out of solution, in the same way that dissolved CO2 appears as bubbles when you uncap a bottle of soda.

These bubbles produce a variety of symptoms, which range from pain in the large joints of the body, such as elbows, shoulders, hips, wrists, knees and ankles, to seizures and unconsciousness. These symptoms tend to increase in severity depending on the rate and amount of pressure change and, if severe enough, can result in death.

  • Bends. Bubbles in the joints which cause rheumatic-like pains. Movement or rubbing the affected parts only aggravates the pain but descent usually solves the problem. The most common symptom of DCS.
  • Creeps. Nitrogen bubbles released under the skin causes the sufferer to feel that a small compact colony of ants are crawling over or under the skin.
  • Chokes. Nitrogen bubbles are caught in the capillaries of the lungs, blocking the pulmonary blood flow causing serious shortness of breath.
  • Staggers. The bubbles affect the blood supply to the brain and nervous system.
If DCS symptoms occur in any crew member or passenger, the pilot should immediately commence a descent to a level at which the symptoms are relieved, and the aircraft should land as soon as possible. The sufferer should be put onto a 100% oxygen supply and urgent medical assistance must be sought on landing even if the patient appears to have recovered.

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