"Most people cannot comprehend what it is like to be sick day after day; because they are accustomed to going to the doctor, taking some medication and soon feeling better.
"Often the most difficult part of having a chronic, debilitating illness, is the lack of support we encounter. People seem to be programmed to think that they have to see someone is bleeding before they can believe they are hurting. Unfortunately, they often ignore what we are saying, because they think we "look" fine."
http://www.invisibledisabilities.com/