"High functioning" and "low functioning"
These are not diagnoses and never were. They try to sum up a whole person in one word, so we describe what a child finds hard and what helps instead.
Applies across the UK
You will hear these a lot, from schools, from family, and sometimes from professionals. They are not part of any diagnostic manual and never have been.
The problem with them is practical, not just about politeness. A child called high functioning is often a child who is coping in public by masking Masking Hiding or holding in the signs of being autistic to fit in, often without meaning to. It is a big reason a child can seem fine at school and fall apart at home. Read the full definition of Masking , which is exhausting and hides how much help they need. Once that label is attached, support tends to be withdrawn. A child called low functioning gets the opposite problem: people stop expecting anything, and stop noticing what the child can already do.
Both labels also pin every difficulty on the child, rather than on a situation that has not been set up to work for them. The National Autistic Society calls functioning and severity labels inaccurate and offensive for exactly this reason, and points out that needs vary and fluctuate.
What works better is plainer and more useful: say what a child finds hard, in which situations, and what help changes it. Where a short phrase is needed, high support needs or low support needs at least describes the support rather than the person.
Other words for this
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You might hear autism
You will hear high functioning and low functioning used about autistic children. We avoid them, because they were never diagnoses and they get in the way: high functioning often means a child is coping by masking, which hides how much help they need, and low functioning lowers what people expect of a child. We describe what your child finds hard, where, and what helps. Using these words yourself is not a mistake, they are everywhere.
Where this comes from
- How to talk and write about autism guide, June 2025 , National Autistic Society. Checked 2026-08-09.
- Higher or Lower? Why using functional labels to describe autism is problematic , Psychiatry-UK. Checked 2026-08-09.
Your child doesn't need a diagnosis to get support
Start with a profile of your child. See what we find. Go from there.