Is this your initial visit with them to apply? If so, they will request that for your medical records from your doctor. You are entitled to a copy of anything they utilize for evidence (i.e. your medical records-this is a good way to get them for free). This way, you can start building a log of all your infections, medical treatments, nebulized medications.... all VERY important things when you go to try and prove your case.
If this is your initial appointment, you have time yet to get documentation to them. Not too much time, but a bit of time,
If this isn't your initial appointment, I would love to give you some pointers. Actually, I'd love to give you some pointers anyways.
Julie