Which of the following is NOT a sign of decompression sickness?

Decompression sickness, often referred to as "the bends," typically manifests through various physiological symptoms resulting from dissolved gases coming out of solution in the body as pressure decreases. Joint pain, nausea, and headaches are all well-documented signs of decompression sickness.

Joint pain, known as "the bends," occurs when nitrogen bubbles form in the tissues and joints, causing extreme pain. Nausea may arise due to the irritation of the inner ear or can be a result of other physiological disturbances related to gas bubble formation. Headaches can also occur as a symptom, possibly linked to cerebral bubble formation affecting brain tissues.

In contrast, dry mouth is not associated with decompression sickness. This symptom is often related to dehydration, anxiety, or other non-specific conditions, which do not directly correlate with the physiological effects of gas bubbles in the body during or after a dive. Therefore, recognizing dry mouth as not a sign of decompression sickness helps differentiate between symptoms related to diving incidents and those related to other factors.