What is a pathologic change of tissues due to disease or injury called?

A pathologic change of tissues due to disease or injury is referred to as a lesion. This term encompasses any abnormal change in tissue structures that can arise from a variety of causes, including disease processes, trauma, or developmental anomalies. Lesions can present as masses, ulcers, or other forms of tissue alteration and are important in clinical diagnosis and treatment planning.

In contrast, infection specifically denotes a disease caused by the invasion of pathogenic microorganisms, which may lead to lesions but does not encompass all types of tissue changes. A contusion describes a bruise resulting from trauma that causes bleeding under the skin without breaking the skin, while ulceration refers to a specific form of lesion characterized by the loss of tissue, typically due to prolonged injury or disease. Lesions serve as a broader category that can include infections, contusions, and ulcerations as potential manifestations of underlying pathologic processes.