I was surprised today to find out that a boy in my office has Crohn's disease. He's been off because he's recently started remicade infusions and he's got an infection. It really knocked me sideways how hidden these things can be. He's never off sick really so I wouldn't have ever known only I've been working on a project with his girlfriend and she was really concerned about him this morning and kind of let it slip he was on immunosupressants which spiked my interest. We then got chatting about stuff and it turns out her dad has pretty severe RA as well and retired early because of it. She had no idea I had RA so it was quite weird to discover all these things about each other having worked together for years.
I wonder how many people at my work are affected/know someone who is affected by a 'secret' auto immune disease. Probably more than I thought!