What happens to nitrogen levels in the body during descent?

During descent, nitrogen levels in the body saturate the tissues due to the increased pressure surrounding the diver. As a diver descends, the atmosphere's pressure increases, which causes nitrogen, which is absorbed by the body's tissues while breathing air, to be absorbed at a higher rate due to Henry's Law.

Henry's Law states that the amount of gas that dissolves in a liquid is proportional to the pressure of that gas above the liquid. Therefore, as pressure increases with depth, more nitrogen gas from the breathing air dissolves into the body’s tissues and fluids, leading to tissue saturation with nitrogen. This process continues as the diver descends further, increasing nitrogen levels in the tissues until a state of equilibrium is reached or the diver ascends. Understanding nitrogen saturation is crucial for divers since it relates to the risk of decompression sickness, which can occur if divers ascend too quickly, causing dissolved nitrogen to form bubbles in the body.