Hemophilia is caused by a defective gene located on the X-chromosome. Symptoms can vary and the severe forms become apparent early in life, while mild cases of hemophilia may go unnoticed until later in life. Common symptoms include spontaneous bleeding or bruising, bleeding into joints with pain and swelling, blood in one's urine or stool, excessive and prolonged bleeding from cuts or tooth extraction and nosebleeds that won't stop.
Attribution: Straight Talk Foundation