blood clotting process
blood disorders
Bruising and Bleeding
Bruising or bleeding after an injury is normal (see also How Blood Clots ). However, some people have disorders that cause them to bruise or bleed too easily. Sometimes people bleed without any obvious triggering event or injury. Spontaneous bleeding may occur in almost any part of the body, but it is most common in the nose and mouth and the digestive tract. People with Hemophilia often bleed into their joints or muscles. Most often, bleeding is minor, but it can be severe enough to be life-threatening. However, even minor bleeding is dangerous if it occurs in the brain. Several symptoms may suggest that a person has a bleeding disorder: Unexplained nosebleeds (epistaxis) Excessive or prolonged menstrual blood flow (menorrhagia) Prolonged bleeding after minor cuts, blood drawing, minor surgical or dental procedures, or tooth brushing or flossing Unexplained skin marks, including tiny dots that may appear red or purple on light skin and brown on dark skin (petechiae), patches that appear red or purple on light skin and brown on dark skin (purpura), bruises (ecchymoses), or small blood vessels that are widened and therefore visible in the skin or mucous membranes (telangiectasias) DR P. MARAZZI/SCIENCE PHOTO LIBRARY Petechiae are small red spots as seen here in the mouth. DR P. MARAZZI/SCIENCE PHOTO LIBRARY Ecchymoses are large purple bruises seen here on the leg. DR P. MARAZZI/SCIENCE PHOTO LIBRARY Sometimes a laboratory test done for some other reason shows the person has a susceptibility to bleeding. 