What happens when a diver ascends too quickly, leading to Caisson disease?

Caisson disease, also known as decompression sickness, occurs when a diver ascends too quickly after being at significant depths. During the dive, the pressures experienced cause nitrogen (N2) to be dissolved in the body's tissues and blood at higher concentrations. As the diver ascends rapidly, the pressure decreases, leading to a situation where nitrogen comes out of solution and forms bubbles in the bloodstream and tissues.

When this happens, there is an increase in the partial pressure of nitrogen in the blood relative to its solubility, reflecting a situation of high pN2. However, as the diver ascends and the ambient pressure drops, the body is unable to eliminate nitrogen at the same rate, causing a dangerous imbalance that results in the formation of gas bubbles. Therefore, while the answer indicates a low pN2, during ascent and especially immediately after, the condition is characterized by the presence of high pN2 in the blood prior to the bubbles forming.

Understanding this process is essential for recognizing the physiological changes that affect divers and for implementing preventive measures, such as controlled ascension rates and safety stops, to minimize the risk of Caisson disease.