What characterizes a disease according to the definitions given?

A disease is characterized as a condition of the living body that impairs normal functioning. This definition emphasizes that a disease goes beyond merely being a minor discomfort or complaint; it indicates that there are significant disruptions to the body’s usual operations. This impairment can manifest in various forms, such as physiological changes, symptoms, or altered behavior that affect a person’s overall health and quality of life.

By specifying that a disease "impairs normal functioning," the definition captures the essence of what distinguishes diseases from other conditions. For example, a cold may involve minor discomfort and not severely disrupt normal activity, which would not be classified as a disease in this strict sense. Additionally, emotional states, while they may affect well-being, are not typically classified as diseases unless they significantly disrupt biological functions, as seen in certain mental health disorders. Therefore, the focus on physical impairment is what aligns broadly with the medical understanding of diseases.