Chest X-ray clear, what could spiroscopy show?

[rainbowlou]

I have had 3 bouts of bronchitis over the last 4-5 months, tried antiobiotics, inhalers, oral steroids,steroid inhalers and still not feeling 100%!
I wake up with a disgusting cough every morning that makes me want to be sick, exercise forget it! Having a drink of water makes me so out of breath..I feel like I smoke and I don’t!
My chest X-ray has come back clear, doctor thinks maybe I have developed asthma but I have a spirometry test booked soon.
So to my question!! What can show up on a spirometry that wouldn't show on an X-ray?
I have googled and wish I hadn’t as I seem to have a lot of symptoms relating to COPD!
Has anyone else been through the same kind of thing and can reassure/advise???x

No idea why I typed spiroscopy!

They're completely different tests. CXR is looking more at the structure & whether there's anything in your lungs that shouldn't be (infection, fluid, etc), spirometry gives more information about the function of your lungs. The spirometry tests are non-invasive & easy to do. Hope that helps :-)

Thank you!