I used to know a Cpl Painter and Finisher who had been retired on medical grounds; not enough breath to complete the basic fitness test - or later, even to walk.
Turned out it was down to lung damage caused by exposure to isocyanates over many years, without sensible protection.
MoD refused compensation - wouldn't even pay for the essential wheel chair!
I don't know what she's doing now, but I hope she's OK.
Rgds SOS