Ask your doctor about a condition called "hypertrophic pulmonary osteoarthropathy." It is an inflamation of the bones, arms, and legs and is associated with chronic lung conditions. Your doctor may give you an x-ray to see if there is any new bone formations, which is an indicator of this condition.
It may also be arthritis; but from what I understand the above condition is more likely and is often mistaken for arthritis.
<b>Edit</b> I should say, is often mistaken for rheumatoid arthritis. There is another kind of arthritis, episodic arthritis, which can also occur. It is often accompanied by a rash and fever and its occurances do not seem to coincide with changes in lung function, unlike hypertrophic pulmonary osteoarthropathy.
