What happens to nitrogen levels in a diver's body during a dive?

During a dive, the pressure surrounding a diver increases, leading to a corresponding increase in nitrogen absorption in their body tissues. As divers go deeper underwater, the partial pressure of nitrogen rises, causing more nitrogen from the breathing gas to dissolve into the bloodstream and accumulate in the body’s tissues. This is due to Henry's Law, which states that the amount of gas that dissolves in a liquid is proportional to the pressure of that gas.

As a result, when divers descend, the nitrogen levels in their bodies significantly increase. This accumulation of nitrogen is important to understand because if divers surface too quickly, it can lead to decompression sickness, also known as “the bends,” as the dissolved nitrogen forms bubbles in the tissues and bloodstream due to a rapid decrease in pressure.

Maintaining awareness of how nitrogen levels change during a dive informs safe diving practices and the need for proper ascent rates and safety stops to allow for safe off-gassing of nitrogen.