I have a condition that when it flares up results in hospital admitiobs and time off work. I find it hard to walk at all when bad. And even talking is hard. However when I am good I can go to the gym. Swim and appear "normal"
I don't want to apply for money but a blue badge would mean I was able to work more when recovering from a bad patch and mean I could rely on others less.
I would obviously only use it when bad.
Can you get one where you have a condition that is changeable?