Which of the following is a key component of a patient's health information that an athletic trainer needs to know?

A key component of a patient's health information that an athletic trainer needs to know is the family history of diseases. Understanding a patient's family medical history is crucial because it can reveal genetic predispositions to certain conditions, which may impact the patient's health and performance in sports. This information helps athletic trainers assess risk factors that could influence injury prevention strategies or rehabilitation protocols.

In contrast, while knowing the patient’s favorite exercise, personal hobbies, and social media activity might offer some contextual information about a patient's lifestyle, these factors do not directly relate to their medical history or current health status. Family history provides essential insights that can guide athlete management and care decisions, making it a priority in the evaluation of a patient's health information.