How is a contusion best defined?

A contusion is best defined as a bruise, which occurs when small blood vessels under the skin break due to an impact or injury, causing bleeding into the surrounding tissues. This results in the characteristic discoloration and tenderness associated with bruises. The definition emphasizes that a contusion does not involve an open wound; the skin remains intact even though there is underlying damage to the blood vessels and soft tissues.

In contrast, the other terms describe different types of injuries. A puncture wound refers to a small hole caused by a pointed object penetrating the skin, while an open wound involves a break in the skin's surface. A cut is a specific type of open wound characterized by a sharp division of tissues. Understanding these distinctions helps clarify the unique nature of a contusion as a closed injury that presents with symptoms like swelling and bruising without breaking the skin.