Which of the following is not a sign or symptom of decompression sickness (DCS)?

The correct answer indicates that a weak and rapid pulse is not typically recognized as a sign or symptom of decompression sickness (DCS). Decompression sickness occurs when dissolved gases, primarily nitrogen, come out of solution and form bubbles in the body due to rapid pressure changes, such as when a diver ascends too quickly.

The signs and symptoms of DCS commonly include severe joint pain, often referred to as "the bends," confusion or disorientation, and gastrointestinal distress like nausea and vomiting. These symptoms are a result of the gas bubbles affecting various tissues and systems within the body, leading to localized pain, cognitive impairment, and digestive issues.

In contrast, while a weak and rapid pulse may occur in response to a variety of medical conditions, it is not specific to DCS. Instead, the more direct signs associated with this condition relate to specific physical pains and cognitive disturbances stemming from the effects of gas bubbles in the body. Thus, weak and rapid pulse does not fit the profile of classic DCS symptoms, marking it as the correct choice for what is not a sign or symptom of decompression sickness.