Autism

Autism in adults: signs that get missed

Around 750,000 autistic adults in England are estimated to be undiagnosed. Here are the signs, what late diagnosis changes, and how to access assessment.

A UCL study in 2023 estimated that around 750,000 autistic adults in England are undiagnosed. Autism in adults was rarely diagnosed until relatively recently, and many parents have their own epiphanies while working out what's happening with their children.

This happened to my husband, who realised he had been misdiagnosed with dyslexia at school; all along he had autism, not diagnosed until his late thirties. If you're a parent reading this and wondering whether what you're seeing in your child also describes you, that's extremely common.

Why autism gets missed in adults

The same mechanisms that cause autism to be missed in girls apply through adulthood: masking, camouflaging, and the fact that autistic adults who are verbally fluent and socially functional are rarely flagged by the systems designed to catch it.

By adulthood, many autistic people have spent decades developing sophisticated strategies for appearing neurotypical: building scripts for social situations, learning which environments they can tolerate, and often developing anxiety, depression, or exhaustion as secondary consequences of the sustained effort involved. Adults seeking help for anxiety or depression may have the underlying autism missed entirely. For people who've been living without the explanation of an autism diagnosis, those conditions often make more sense in retrospect.

Signs of autism in adults that are commonly missed

The textbook presentation, the non-verbal child lining up objects, describes a small minority of autistic people. Adult autism, particularly in people without intellectual disability, often looks like this:

Social and communication

  • Difficulty with unwritten social rules; following the literal meaning of words rather than the implied one
  • Finding small talk effortful or meaningless; preferring deeper, more structured conversation
  • Misreading tone or body language; frequently misinterpreting others' intentions
  • Friendships that feel one-sided, draining, or that involve extensive preparation and debrief
  • Social anxiety that's specifically about unpredictability or not knowing the rules, rather than general shyness

Sensory and environment

  • Strong reactions to certain sounds, textures, smells, or light
  • Difficulty in busy, unpredictable environments: open-plan offices, shopping centres, crowded social events
  • Strong food preferences or aversions related to texture, colour, or temperature

Routine and regulation

  • Significant distress at disruption to routine or last-minute changes
  • Difficulty switching between tasks; transitions are effortful even between enjoyable things
  • Periods of exhaustion or burnout after socially demanding phases
  • Autistic burnout: extended periods of significant fatigue, reduced functioning, and withdrawal after prolonged masking

Pattern recognition

  • Relating to descriptions of autism when they come from autistic people rather than clinical checklists
  • A sense of having always felt different without being able to explain why
  • Relief when an autistic child's experience is described and it resonates

None of these is diagnostic on its own. But if several are consistently true, an assessment is worth pursuing.

How to get an autism assessment as an adult

Start with your GP. Explain specifically what you're experiencing and why you think autism might be relevant. NHS referrals for adult autism assessment face long waits, in some areas over two years, but it is available.

Under NHS Right to Choose, you can ask your GP to refer you to an approved independent provider rather than joining the local waiting list; this can significantly reduce waiting time in some areas. Private adult autism assessment typically costs £1,200–2,000 and produces a clinically valid report. Look for clinicians with specific experience of late-diagnosed adults and the female autism phenotype if that's relevant.

A diagnosis in adulthood doesn't change your history, but it does change how you understand it, and what support you can access going forward.


Neuroequipped provides research-grounded information for parents and educators. It is not medical advice. If you have concerns about your own presentation, speak to your GP.