What term describes the bruising or discoloration that appears as black and blue marks on the skin?

The term that accurately describes the bruising or discoloration appearing as black and blue marks on the skin is ecchymosis. This term specifically refers to the discoloration that occurs due to bleeding underneath the skin, and it typically presents as a large area of bruising. Ecchymosis occurs when small blood vessels leak blood into the surrounding tissues, often resulting from trauma or injury.

While hematoma, contusion, and lesion are related terms, they describe different phenomena. A hematoma refers to a localized collection of blood outside of blood vessels, often more substantial and raised compared to ecchymosis. A contusion is a broader term for a bruise, which can include ecchymosis as a type of contusion. A lesion is any abnormal change or injury to tissue, making it a more general term that does not specifically refer to bruising or discoloration. Understanding these distinctions helps clarify why ecchymosis is the correct term for the bruising described in the question.