Haemophilia B is a genetic disorder that affects the blood's ability to clot. It is caused by a deficiency of factor IX, a protein essential for blood coagulation. Individuals with this condition may experience prolonged bleeding after injuries, surgeries, or even spontaneously without any apparent cause. This condition is inherited in an X-linked recessive pattern, primarily affecting males. Women can be carriers and may pass the gene to their children. Treatment often involves regular infusions of factor IX concentrate to help manage bleeding episodes and prevent complications.