What is the common term for the process of nitrogen leaving the body after diving?

The process of nitrogen leaving the body after diving is commonly referred to as decompression. This term specifically describes the regulated and gradual ascent a diver makes to allow inert gases, primarily nitrogen, that have been absorbed into the tissues under increased pressure, to safely exit the body as the pressure decreases.

During a dive, the body's tissues absorb nitrogen due to the higher partial pressures underwater. If a diver ascends too quickly, this nitrogen can form bubbles in the tissues and bloodstream, leading to decompression sickness (also known as "the bends"). To avoid this, divers follow a carefully planned ascent that allows time for the nitrogen to be released slowly and safely through the lungs, which is why the term decompression is used in this context.

While desaturation does refer to the reduction of nitrogen levels in the body, it is not as commonly used as "decompression" in the context of dive safety. Exhalation and expulsion refer more to the general act of breathing out air and do not specifically address the unique process related to nitrogen off-gassing post-dive. Hence, decompression is the most accurate and recognized term for this crucial aspect of diving safety.