how do you get decompression sickness?

Answer 1

Decompression sickness, aka nitrogen narcosis or the bends, occurs when the atmospheric pressure on a person is suddenly decrease. Air, which is mainly nitrogen, dissolves in your blood. The amount that dissolves is related to the atmospheric pressure you body is at. If the pressure is abruptly decreased, such as ascending to fast while scuba diving, the nitrogen in you blood comes out of solution and forms bubbles. These bubbles cut off blood flow in small blood vessels all over you body resulting in sever pain, possible organ damage (like strokes), sometimes seizures or even death.

The treatment is to put the person in a hyperbaric chamber. That is increase the pressure to the nitrogen again dissolve in the blood. The drop the pressure more slowly so the nitrogen will be exhaled through the lungs rather than bubbling up.