Bruises (contusions) occur when
small blood vessels under the skin tear or rupture, most often from a twist,
bump, or fall. Blood leaks into tissues under the skin and causes a
black-and-blue color that often turns purple, red, yellow, and green as the
ByHealthwise Staff Primary Medical ReviewerWilliam H. Blahd, Jr., MD, FACEP - Emergency Medicine Specialist Medical ReviewerH. Michael O'Connor, MD - Emergency Medicine
How this information was developed to help you make better health decisions.