We should really avoid the terms “low-functioning” and “high-functioning”. First of all they don’t say much, as many “high-functioning” autistic people have enormous difficulties in daily life exactly because at first sight they look relatively normal and most NTs don’t take their needs into consideration or understand them, which can cause crises and even meltdowns (and of course isolation). Secondly many so-called “low-functioning” autistic people have an enormous potential and a lot of other gifts to share.
But worse of all the terms “low-functioning” and “high-functioning” are not medical terms, but terms coined by Hans Asperger himself, who lived in the Nazis period and wanted to save some of his patients from extermination, so he called them “high-functioning”. We didn’t know about this until yesterday and were shocked at the history of the terms. More info here.
We really think it is better to avoid the terms “low-functioning” and “high-functioning”.