People with COPD might be eligible for Employment and Support Allowance (which has replaced Incapacity Benefit and related benefits) but it would depend upon individual circumstances.
Firstly, it would be necessary to show that the condition was severe enough to meet the official criteria for 'incapacity'. Secondly, the applicant's National Insurance contributions record (for contribution-based ESA) or means (such as savings, for income-based ESA) would need to be taken into account.
See here:
http://www.lunguk.org/you-and-your-lungs/livin g-with-a-lung-condition/welfare_benefits_for_p eople_living_with_a_lung_condition.htm
and here:
http://www.direct.gov.uk/en/DisabledPeople/Fin ancialSupport/esa/index.htm
For further advice, phone the BLF Helpline:
http://www.lunguk.org/supporting-you/helpline- advice-service/
Chris