Final answer:
The patient's reports of not having nausea, and experiencing pain and heartburn are subjective data, as they are symptoms that the patient feels and cannot be objectively measured.
Step-by-step explanation:
The data provided by the patient stating that she does not experience nausea but reports pain and heartburn, especially after eating popcorn, would be categorized as subjective data. Symptoms like nausea, pain, and heartburn are subjective because they are felt or experienced by the patient and cannot be clinically confirmed or objectively measured. Despite their subjective nature, these symptoms are crucial for diagnosis and understanding a patient's condition. Clinicians sometimes attempt to quantify these symptoms using scales like the Wong-Baker Faces pain-rating scale, or by measuring physiological responses such as skin conductance fluctuations caused by stressors like pain.