It's hard sometimes... and sometimes others don't get it. It even is hard for my family to get sometimes. I have an auto-immune disease, called sarcoidosis. I don't look sick on the outside, I look lazy I guess to a lot of people.
On the inside, it can affect any organ of my body. It has affected most severely my lungs (scar tissue, granulomas, making it difficult to breathe) and my heart (heart arrhythmia). It also affected my skin very badly (severe rashes, itching, painful break-outs all over that last for months). And there's a lot of joint pain on and off. I was misdiagnosed with everything from scabies and asthma to cancer (scary!!!) before they found the sarcoid. And there were a good deal of dr.s along the way who thought it was just hypochondria, or that I was whiny and lazy.
Thankfully I'm in remission now, but when I finally got diagnosed I had gotten to the point I was sleeping 20 hrs per day, getting heart arrhythmia every 30 seconds or so that made me cough, and couldn't walk a half a block without feeling like I was going to collapse. I lost a lot of friends, who turned out not to be the greatest friends, because I wasn't up for much and was always being a downer.
There have been some times when I wanted to cry. Times when my own family, even though they love me and try to be understanding, would reach their breaking point with my helplessness and get annoyed that I wasn't doing more. Trying to make other people understand, they really don't get why I can't just get up and 'power through it' like everyone else who's tired and achy.
I think the meanest people were was at Walt Disney World. I was in a wheelchair and frankly people treat you like you're trying to scam the system or something when you're in a wheelchair at Disney World unless you have a visible cast or deformity or something. Not the workers, but other guests. It was hurtful.
So there's two approaches basically. Give people the quick version, which doesn't give them a good idea of what I'm going through but saves me the sob story. Or go on and on about it explaining it in hopes people will understand,
But I think that this is just the kind of think people don't generally understand unless they go through it themselves. It's hard to wrap your brain around physical limitations and all that they encompass until you have to live with them.