A contusion (kun-TOO-zhun), or bruise, of the knee is an injury to the skin and underlying tissue of the knee.
More to Know
A contusion, or bruise, forms when soft tissue in the body is crushed but the skin doesn't break. When this happens, blood from broken capillaries (small blood vessels) near the skin's surface may leak out under the skin. With no place to go, the blood gets trapped, often forming a red or purplish mark that hurts when you touch it.
As a contusion heals, it may turn different colors, from red and purple to black and blue and then to green, yellow, and light brown before fading away.
Keep in Mind
Applying a cold compress to a contusion may help minimize swelling and bruising. Seek medical attention if a contusion doesn't heal or continues to be painful.
All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.