Hemophilia (heem-o-FILL-ee-ah) is a rare, inherited bleeding disorder in which your blood doesn’t clot normally. If you have hemophilia, you may bleed for a longer time than others after an injury. You also may bleed internally, especially in your knees, ankles, and elbows. This bleeding can damage your organs or tissues and, sometimes, be fatal.
Children with mild hemophilia may not have symptoms until they have excessive bleeding from a dental procedure, an accident, or surgery. Males with severe hemophilia may bleed heavily after circumcision. Bleeding can be obvious (external bleeding) or hidden within the body (internal bleeding).