Who is visible disability will immediately notice such people who sit in a wheelchair but people with invisible impairment will not immediately notice such fatigue. We may have low expectations of the people who sit on wheelchair because we think he/she is unable lifting things and high expectation for the person who has fatigue because we cannot judge the invisible disability of him/her. Both conditions of disability equally frustrate to each individual.
Let say I have an invisible disability that no one knows. I do not tell because I am ashamed of it or do not want to be the one that different among my friends and got pity. I stigmatize with my condition. Then why I feel stigmatized? Nobody ever stared and said bad things to me.
Unfortunately, the media most of time influence our opinion, such as news that we read in newspaper that people with an illness “limited” to do things regarding they are not “normal”, sometime comedian on Television show using disability as a source for humor that we may don’t realize that could cause stigmatization.
However, the media also offer the source as solution to decrease stigma among people, the media has the power to educate and influence our opinion. The media can use to spread positive messages, which help to understand about impairments that have misconceptions among people. According social psychology on discrediting psychiatric stigma, the stigmatization of every individual has a different level depend on knowledge about disability. The people who have more information about disability are less stigmatizing than people who have less knowledge about disability.
Lastly, the media and stigmatization among people could be a solution and a problem at the same time. It is hard to expect the reaction of each individual concerning disability.
Non-excluding Design 
I think that you are right in that a large part of the stigmatization will have to be dealt with through the spreading of information and positive messages. In Sweden there is a theater where the actors all have cognitive impairments. This groups has given a new face to people with various cognitive impairments, which I think is a very important phase in destigmatizing impairments.