What is the primary characteristic of symptoms?

The primary characteristic of symptoms is that they are experienced internally by the patient. Symptoms refer to subjective experiences related to a health condition, such as pain, fatigue, or nausea. These sensations are personal and can vary greatly from one individual to another. Unlike signs, which are observable phenomena, symptoms reflect the patient's internal state and cannot be directly measured or perceived by others without the patient's report.

The emphasis on the patient's subjective experience highlights the importance of communication in healthcare, where patients must articulate how they feel for healthcare providers to understand and assess their condition effectively. This characteristic sets symptoms apart from other aspects of medical diagnosis, reinforcing that a thorough patient assessment often relies heavily on their descriptions of their internal experiences.