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
colors, including purplish black, reddish blue, or yellowish green, as the
Most bruises are not serious and will go away on their own within 2
to 4 weeks. Sometimes, gravity causes them to spread down the body. A leg
bruise usually will take longer to heal than a bruise on the face or
Severe bruising, swelling, and pain that begin within 30 minutes of
an injury may mean a more serious injury, such as a severe sprain, dislocation,
Sudden unexplained bruising or a sudden increase in the frequency
of bruising may be a sign of an abnormal type of bruising that may be caused by
medicine side effects, a bleeding or clotting disorder, or a medical
William H. Blahd, Jr., MD, FACEP - Emergency Medicine & H. Michael O'Connor, MD - Emergency Medicine
How this information was developed to help you make better health decisions.
The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.