What is the condition characterized by sustained physical harm or mental anguish?

The condition characterized by sustained physical harm or mental anguish is best identified as abuse. Abuse encompasses various forms of maltreatment, including physical, emotional, and psychological injuries inflicted on an individual over an extended period. This can manifest as violence, neglect, or any action that leads to severe distress and harm to an individual’s well-being.

While the term injury refers to physical damage or harm typically resulting from an accident or violence, it doesn't necessarily imply the ongoing nature or the psychological aspects of suffering that define abuse. Malpractice, on the other hand, is specifically related to negligence by professionals, particularly in medical or legal fields, and does not encompass the broader social and emotional dimensions of abuse. Trauma might indicate a response to a distressing event, but it does not fully capture the ongoing and repetitive nature of mistreatment that abuse implies.

Thus, the term abuse accurately denotes the persistent nature of harm—both physical and mental—making it the most fitting answer to the question.