The bends” is decompression sickness that occurs when deep sea divers come up to the surface too quickly causing painful gas bubbles in the blood. Suggest reasons why air bubbles in the blood might be painful.

Decompression sickness, also called generalized barotrauma or the bends, refers to injuries caused by a rapid decrease in the pressure that surrounds you, of either air or water. It occurs most commonly in scuba or deep-sea divers, although it also can occur during high-altitude or unpressurized air travel.