bruise

A bruise, or contusion, is a common skin lesion caused by blunt trauma that damages small blood vessels beneath the skin, leading to bleeding into the surrounding tissue without an open wound.

The leaked blood clots and produces discoloration that changes as the body reabsorbs it. In the first 24 to 48 hours the area often appears red or dark purple, then blue or green as hemoglobin is broken down to biliverdin, and finally yellow-brown as bilirubin is cleared.

Causes include impacts from sports, falls, accidents, or injections. Larger contusions or those in older adults or people with bleeding disorders or who take anticoagulants are at higher risk for prolonged bruising.

Diagnosis is usually clinical. A bruise is distinguished from a hematoma by whether the blood remains confined to the tissue; severe swelling, deformity, numbness, or inability to move a limb may indicate a fracture or deeper injury and may require imaging.

Treatment generally follows the RICE approach: rest, ice, compression, and elevation in the first 24 to 48 hours. Apply ice for 15 to 20 minutes several times a day, use a compression bandage if advised, and keep the limb elevated to reduce swelling. Analgesia such as acetaminophen can help; NSAIDs may be used with caution, as they can affect clotting. Avoid heat early and avoid squeezing the area.

Most bruises heal in days to a couple of weeks, depending on size and location. Seek medical attention for unusually large or painful bruises, bruising that lasts several weeks, signs of infection, persistent swelling, or if there is suspicion of fracture or a bleeding disorder. Prevention includes protective gear, proper technique, and managing underlying conditions that affect bleeding.