Decompression sickness is primarily caused by what physiological process?

Decompression sickness, often referred to as "the bends," primarily occurs due to the physiological process of excessive nitrogen absorption by the body while under pressure. As divers descend into the water, the pressure increases, which causes more nitrogen from the air they breathe to dissolve into their tissues and bloodstream. The deeper a diver goes, the greater the pressure, and thus the more nitrogen is absorbed.

When a diver ascends too quickly, the pressure decreases rapidly, and the nitrogen that was previously dissolved in the body begins to form bubbles. These bubbles can cause a variety of serious physiological problems as they expand and move through the body, potentially damaging tissues and organs. Therefore, managing nitrogen absorption is critical, and divers are trained to ascend slowly to allow the body adequate time to eliminate the excess nitrogen in a safe manner.

The other choices, while they may contribute indirectly to the risks of diving, do not directly describe the fundamental physiological process leading to decompression sickness. Hence, understanding this primary cause is essential for safe diving practices and effective preventative measures.