Haematological
Haemophilia B
Inherited Factor IX deficiency.
Overview
Inherited Factor IX deficiency.
Also known as: christmas disease, factor 9 deficiency
In-depth guidance
A structured clinical overview of Haemophilia B — symptoms, red flags, causes, and care pathways — is being prepared by our clinical reviewers. In the meantime:
⚠ When to seek urgent care
Sudden severe symptoms, breathing difficulty, chest pain, confusion, fainting, severe bleeding, or any rapidly worsening illness need urgent assessment. Call your local emergency number.