note It's actually been that way in the disability activist community since the 'Social Model of Disability' was pioneered by British Disability Rights activists in the 1970s, but frequently actually disabled people get spoken over by educators and media professionals. As of the mid-2010s, the treadmill turned again, and now 'disabled' is again the preferred term.
The term used to describe people with life-changing diseases or injuries followed a similar path, from 'crippled' to 'handicapped' to 'disabled' to 'physically challenged' when terms like 'handi-capable' and 'differently abled' were proposed, it came across as too clunky and people generally agreed to stop messing with it. After decades of that being used as an insult, 'retarded' is now considered so offensive that some people want it classified as hate speech. As these terms fell into common use as insults, they were replaced by a kinder and gentler term: 'mentally retarded'.
The words 'idiot', 'moron', and 'imbecile' started as clinical terms, referring to people with IQs below 75, 50, and 25, respectively.
Some of these examples result from the euphemism treadmill, whereby terms are repeatedly replaced as the previous word falls into such a state of misuse that it cannot be recovered.
