Final answer:
Activities increasing the risk of decompression sickness include alcohol and drug use, which can negatively impact the body's response to pressure changes when diving.
Step-by-step explanation:
Activities that may increase the risk of decompression sickness include alcohol use and drug use. Both alcohol and drugs can have negative effects on the body's capacity to cope with pressure changes during a dive, potentially contributing to the onset of decompression sickness, which is a condition in which dissolved gases come out of solution in bubbles inside the body due to a reduction in external pressure. The condition, known by divers as "the bends," involves a variety of symptoms such as joint pain and rashes, and in severe cases, can lead to paralysis or death. To mitigate the risks of decompression sickness, divers must follow standard safety practices such as ascending slowly and making decompression stops. If preventative measures fail, treatments such as hyperbaric oxygen therapy within decompression chambers are utilized.