Final answer:
Signs and symptoms of disease help doctors in diagnosing a patient's condition. In Brian's case, his fever is a sign, while his nausea and migraine are symptoms.
Step-by-step explanation:
Signs and symptoms of disease help doctors in diagnosing a patient's condition. Signs are objective, measurable findings that can be observed by others, such as a fever or rash. On the other hand, symptoms are subjective experiences reported by the patient, such as nausea or headache.
In Brian's case, his fever of 38 °C (100.4 °F), which can be objectively measured using a thermometer, is a sign of his illness. His complaint of nausea and constant migraine are subjective experiences and thus considered symptoms. These symptoms are reported by Brian himself and cannot be measured or observed by others.
It is important for healthcare professionals to consider both signs and symptoms when evaluating a patient, as they provide valuable information about a person's health and can help in the diagnosis and treatment of diseases.