Scuba divers sickness when flying a plane after dive?

Answer 1

Decompression sickness is caused by reducing the pressure on your body too quickly. Dissolved gasses can turn into bubbles very much like cracking the cap on a soda bottle. The gas bubbles in your blood and joints is very sore and can cause permanent damage or death. Although this usually happens when you come up from depth it can also happen if you go up in the air where the atmospheric pressure is less. Even though most planes have pressurised hulls and the risk of DCS would be very low indeed, flying is generally avoided for a period after diving. In a diving accident where a patient needs helicopter air lift, the helicopter keeps a low altitude for the same reason.