An inherited blood disorder passed from a parent to their child through genes. Hemophilia delays the clotting of the blood, causing difficulty in controlling bleeding due to lack of clotting factor protein in the blood. There are 13 main factors (identified by roman numerals) in blood that work together to produce a clot. If one factor is missing, the chain reaction is broken and clots will not form properly, causing a person with hemophilia not to bleed faster, but to bleed for longer periods of time. If not treated early on, hemophilia can lead to crippling pain, internal bleeding into muscles and joints, severe joint damage, disability, and early death. There are various levels of severity. A mild form of hemophilia may be having few bleeding episodes, but may require taking precautions if having surgery, or after a serious injury. Severe hemophilia can lead to bleeding spontaneously when there is no obvious cause for the bleeding. Hemophilia affects mostly males.