Bleeding is mainly cutaneous-mucosal:
- bleeding gums,
- bleeding from tonsils,
- heavy periods,
- gastrointestinal bleeding,
However, haematoma and haemarthrosis are rare and are only seen in patients with marked concomitant factor VIII deficit.
These may be either spontaneous or induced, for example by surgery or dental extraction.
Clinical signs vary from one individual to another, even for the same abnormality within a single family. This heterogeneity accounts for the difficulty of diagnosis and for the wide discrepancy in patient age at diagnosis.