http://www.nhlbi.nih.gov/health/dci/Diseases/hemophilia/hemophilia_what.html
National Heart, Lung, and Blood Institute, National Institutes of Health
This publication discusses hemophilia (heem-o-FILL-ee-ah). It is a rare, inherited bleeding disorder in which your blood doesn’t clot normally. The publication links to more information about the disorder, including causes, signs and symptoms, diagnosis, and treatments.