Final answer:
In the scenario, where a patient with a migraine headache reports feeling nauseated, the nausea is considered a concomitant symptom as it is associated with the migraine and is a subjective report from the patient.
Step-by-step explanation:
The nurse is assessing the character of a patient's migraine headache and asks, "Do you feel nauseated when you have a headache?" The patient's response is "yes." In this case, the finding of nausea is a concomitant symptom. A symptom is subjective and is reported by the patient, not measured or directly observed by the clinician. Since the nausea is associated with the migraine but is not the primary condition itself, it is considered a concomitant, or accompanying, symptom. Symptoms like nausea and pain are crucial in the diagnostic process, even though they rely heavily on the patient's perception and the accuracy of their report.