What is the term for something related to or caused by disease?

The term that refers to something related to or caused by disease is "morbid." This word is typically used in contexts where diseases or unhealthy conditions are being discussed. The adjective "morbid" describes a state that is indicative of disease or unhealthy psychological states, and it is often applied in medical and health-related discussions.

For example, in medical terminology, "morbid" can refer to a particular condition, behavior, or state that is pathological or associated with illness. In contrast, while "morbidity" relates closely to disease, it specifically refers to the incidence of illness within a population or the degree of ill health. "Vitality" signifies strength or energy and is associated with good health rather than illness, while "healthful" pertains to promoting health or being beneficial for health.

Thus, "morbid" accurately captures the essence of something that pertains directly to disease or conditions resulting from disease.