Answer by  
                                                                                          Conor (20)
                                                            
                          
                          
                                                          Yes, Coumadin causes bleeding.  Coumadin is the brand name for a drug called warfarin.  It is an antithrombotic used to prevent and treat blood clots.  It does this by thinning the blood and this can cause severe bruising and bleeding as a side effect.  It is often stopped prior to surgery to reduce bleeding risk.