What is a contusion?

A contusion is defined as a bruise that occurs due to trauma, leading to damage to the small blood vessels beneath the skin. When these blood vessels rupture, blood leaks into the surrounding tissue, causing a discoloration that typically appears as a black-and-blue mark. This process is part of the body's response to injury, and the resulting swelling and tenderness are due to the accumulation of blood and fluid in the affected area.

Understanding the definition of contusion as a bruise highlights the distinction between structural damage (as seen in a contusion) versus other types of skin or tissue injuries. For example, a skin infection involves pathogens invading the skin, while a tear in the skin refers to an open wound that compromises the skin's integrity. A benign growth, on the other hand, is a non-cancerous tumor that does not involve bruising or blood vessel damage. By clarifying these differences, it becomes clear why the definition of a contusion centers around the bruising effect from damaged blood vessels rather than other skin conditions or injuries.