Medical emergencies are correctly identified by their signs and symptoms. Which one of the following is a symptom rather than a sign?

The correct answer is chest pain, which is classified as a symptom rather than a sign. Symptoms are subjective experiences reported by the patient that indicate a potential health issue but cannot be measured or observed directly by someone else. In this case, chest pain is something that only the person experiencing it can truly perceive and describe.

On the other hand, signs are objective findings that can be observed or measured by a healthcare professional. For example, blue lips indicate a lack of oxygen in the blood and can be visually assessed; sweating can be noticed during a clinical examination, and a weak pulse can be detected with a pulse check. Each of these can be observed directly and are indicative of underlying medical conditions.