A person with haemophilia can bleed without having an external wound and without seeing any blood flowing. This is the case of internal bleeding, i.e. bleeding into joints, muscles or internal organs.
It is good to remember that no fall or other injury needs to be preceded in order to cause an internal bleeding. Bleedings without apparent cause (spontaneous bleedings) occur more frequently in people with severe haemophilia, precisely because they have very low levels or complete lack of coagulation factor.