Hemophilia Also called: Christmas disease, Factor IX deficiency, Factor VIII deficiency Summary Hemophilia is a rare disorder in which the blood does not clot normally. It is usually inherited. Hemophilia usually occurs in males. If you have hemophilia, you have little or no clotting factor. Clotting factor is a protein needed for normal blood clotting. Without it, you may bleed for a long time after an injury or accident. You also may bleed into your knees, ankles, and elbows. Bleeding in the joints causes pain and, if not treated, can lead to arthritis. Bleeding in the brain, a very serious complication of hemophilia, requires emergency treatment. The main symptoms of hemophilia are excessive bleeding and easy bruising. Blood tests can tell if you have it. The main treatment is injecting the missing clotting factor into the bloodstream. You may need it on a regular basis, or just when bleeding occurs. NIH: National Heart, Lung, and Blood Institute National Heart, Lung, and Blood Institute Related Issues Carrier Diagnosis World Federation of Hemophilia Inhibitors Centers for Disease Control and Prevention Clinical Trials ClinicalTrials.gov: Blood Coagulation Disorders National Institutes of Health ClinicalTrials.gov: Hemophilia A National Institutes of Health Diagnosis and Tests Coagulation Factors Test American Association for Clinical Chemistry Fibrinogen Test American Association for Clinical Chemistry Hemophilia Diagnosis Centers for Disease Control and Prevention How Is Hemophilia Diagnosed? National Heart, Lung, and Blood Institute PT and INR Test American Association for Clinical Chemistry PTT Test American Association for Clinical Chemistry Encyclopedia Factor IX assay Factor VIII assay Women Familiy Planning and Pregnancy World Federation of Hemophilia Find an Expert Find a Hematologist American Society of Hematology National Heart, Lung, and Blood Institute National Heart, Lung, and Blood Institute Start Here Frequently Asked Questions: Hemophilia World Federation of Hemophilia Hemophilia Facts Centers for Disease Control and Prevention Hemophilia in Pictures World Federation of Hemophilia Learning about Hemophilia National Human Genome Research Institute What is Hemophilia? National Heart, Lung, and Blood Institute Genetics Genetics Home Reference: hemophilia National Library of Medicine What Causes Hemophilia? National Heart, Lung, and Blood Institute Array Hemophilia Hemophilia A Hemophilia B Partial thromboplastin time (PTT) Children Hemophilia (For Parents) Nemours Foundation How to Deal with Hemophilia Nemours Foundation Teenagers Hemophilia (For Teens) Nemours Foundation Statistics and Research Hemophilia Data and Statistics Centers for Disease Control and Prevention Treatments and Therapies Hemophilia Treatments Have Come a Long Way Food and Drug Administration How Is Hemophilia Treated? National Heart, Lung, and Blood Institute What Is a Blood Transfusion? National Heart, Lung, and Blood Institute Living With Living with Hemophilia National Heart, Lung, and Blood Institute Journal Articles Hemophilia Symptoms What Are the Signs and Symptoms of Hemophilia? National Heart, Lung, and Blood Institute Latest News 2 New Findings Offer Hope for Those with Severe Hemophilia HealthDay Review Finds Mixed Success with Hemophilia Treatment HealthDay