Which of the following is a sign of potential elder abuse that an HHA should report?

Unexplained bruises or injuries are a significant sign of potential elder abuse that should be reported by a home health aide. This option highlights a physical manifestation of possible harm, which could indicate that the elder is being subjected to neglect or physical abuse. Unlike other choices, unexplained bruises or injuries are concrete and raise immediate concerns about the individual's safety and well-being.

Frequent hospital visits might suggest a variety of health issues but don’t inherently indicate abuse. Similarly, refusal to take medication can stem from many factors, including cognitive issues, objections to the medication, or misunderstandings about its necessity, rather than abuse. Changes in appetite can reflect numerous health or psychological conditions and are not specific indicators of abuse. Observing physical signs of injury, especially if they cannot be adequately explained or are inconsistent with the elder's situation, demands urgent attention and intervention.