Hemophilia is a disorder of the blood clotting system that prevents blood from clotting normally and stopping bleeding. It is caused by deficiencies in certain clotting factors, especially factors VIII and IX. Hemophilia is located on the X chromosome and is predominantly found in males, as they only have one X chromosome. Symptoms include abnormal bleeding and bruising, especially into joints and muscles. There is no cure for hemophilia, but regular injections of the missing clotting factor can control symptoms. Patients must take precautions to prevent injury but are encouraged to exercise and participate in normal activities.