Final answer:
Subjective data, like pain, dizziness, and nausea, are experiences reported by the patient and cannot be measured objectively. Clinicians may quantify these experiences using tools like the Wong-Baker Faces pain-rating scale. Referred pain is a form of subjective data where the perceived location differs from the actual source.
Step-by-step explanation:
Information perceived only by the affected person, such as pain, dizziness, and nausea, is considered subjective data. Unlike objective data, which can be observed and measured, subjective data are reported directly by the patient and cannot be independently confirmed through physical examination or diagnostic tests. For example, clinicians may use the Wong-Baker Faces pain-rating scale to have patients rate their pain perception on a scale of 0 to 10. This attempt to quantify subjective experiences can help in the assessment of symptoms and aid in the diagnosis and treatment of diseases, even though such data is inherently subjective and variable.
Referred pain is another example of subjective data where pain is not felt at the site of the problem but in a different location, which makes objective determination even harder. A conscious perception of visceral sensations may be mapped onto specific regions of the body, as seen in a referred pain chart.