What is acquired haemophilia?
Acquired haemophilia is not inherited, and cannot be passed on in the family. It may develop suddenly when a person’s immune system starts to interfere with his/ her own clotting factors by mistake. This reduction in the amount of clotting factor prevents the blood from clotting naturally, so bleeding continues.

Who gets acquired haemophilia?
Acquired haemophilia is very rare, occurring in about 1-4 per million people every year. Men and women are equally likely to be affected. It is usually seen in older people, but has been associated with a wide variety of conditions, such as rheumatoid arthritis, pregnancy and as a reaction to certain drugs.

Last updated: March 2009
CAID/SUEC/HAEM28