Heather is a middle-aged lady who presents to your clinic complaining of significant breathlessness. She walks in to your clinic room evidently tachypnoeic. These symptoms have developed over the last 12 months. She reports a non-productive, dry cough, which is particularly worse in the mornings. Her occupational history includes working as a primary school teacher. She is an ex-smoker but quit many years ago. She suffers with rheumatoid arthritis (diagnosis 17 years ago) for which she was prescribed methotrexate 12 months ago.
These are the spirometry results. What is your interpretation?