In the case of an older adult experiencing muscle weakness, which of the following is classified as a symptom?

In the context of health assessments, symptoms are subjective experiences reported by the patient that indicate an abnormal condition. The sensation of tingling in the face and tongue directly reflects the individual's experience of discomfort or unusual physical sensations. This qualifies it as a symptom because it is something the older adult perceives and communicates, indicating a possible underlying issue that requires further evaluation.

On the other hand, new medication, aging, and a new salt substitute are not classified as symptoms. The new medication is an external factor that may influence the patient's condition, but it is not a sensation or experience. Aging is a biological process, not an individual's experience of health. Similarly, a new salt substitute is an environmental factor that may affect health but does not represent a directly perceived symptom of the individual's condition. Therefore, tingling of the face and tongue stands out as the clear symptom based on the personal experience of the individual.