Why High-Functioning Autism Is Hard to Define

High-functioning autism (HFA) is neither an official diagnosis nor is there an agreed-upon definition of what the term means. In the broadest sense of the term, high-functioning autism may mean any of the following:

  • A person with traits significant enough to merit an autism diagnosis, but with low support needs
  • An autistic person who is largely able to navigate a school or work environment
  • A person who can "pass" for neurotypical because they chronically mask at work, school, socially, and/or home (suppressing some behaviors and mimicking the behaviors of others)
  • A person who, at one point, had an Asperger's syndrome diagnosis—a diagnosis that is no longer in use and not accepted by the autistic community

Adding to the confusion is the fact that many autistic people are bright and accomplished yet simultaneously have a high need for support (related to anxiety and sensory sensitivity issues, for example, that significantly impact their daily functioning).

A boy and a girl drawing with colored pencils in art class
Hero Images / Getty Images

HFA vs. Asperger's Syndrome

Until 2013, many people who might be said to have high-functioning autism were diagnosed with either Asperger's syndrome or PDD-NOS (pervasive developmental disorder not otherwise specified). 

But, there are differences that set those two diagnoses apart:

  • Asperger's syndrome was a distinct diagnosis which described a person of average or higher-than-average intelligence and age-appropriate language skills who also had significant social and communication challenges.
  • PDD-NOS was a catch-all diagnosis. Often understood to mean the same thing as "high-functioning autistic," it really incorporated individuals at all functional levels whose symptoms didn't fully correlate with the mainstream perception of classic autism.

Perhaps more significantly, people with Asperger's syndrome often had different autism presentations than autistic people with higher IQs. For example, anxiety was often a symptom of Asperger's syndrome but not one shared by everyone who might be described as being "high-functioning." One possible explanation for this is that people diagnosed as having Asperger's may have masked a lot, contributing to higher levels of anxiety.

As of 2013, with the publication of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), neither PDD-NOS nor Asperger's syndrome is an official diagnostic category in the United States. Both are now included under the diagnosis of autism spectrum disorder (ASD). People who would have been classified as "high-functioning" are now described as being "Level 1 ASD."

HFA and Level 1 Autism

Autism spectrum disorder is a single diagnosis that encompasses many people who are very different from one another. So, to clarify these differences, the DSM-5 also includes functional levels. People who are bright and verbal are generally given the diagnosis of Level 1 ASD.

Autistic self-advocates and some experts problematize the use of functioning labels and levels because of the way those distinctions materially separate people into "good/useful" autistics versus "bad/not worth living" autistics; this claim is based in truth due to the popularity of eugenicist movements in the autistic community's history.

Asperger's and Eugenics

Hans Asperger, the man who claimed he discovered autism and who created the Asperger's syndrome label, had his research funded by the Nazi regime and specifically protected autistic children he labelled as having Asperger's and therefore being intelligent, while allowing other autistic children to perish under euthanasia.


This historical context is a big reason that the Asperger's label is no longer in use by medical professionals and is no longer welcomed by the autistic community.

Still, the distinction in the DSM-5 doesn't offer a clear characterization of what Level 1 ASD actually is. For example:

  • People with Level 1 ASD without supports may experience noticeable differences and difficulties communicating with neurotypical people.
  • They might have difficulty initiating social interactions, and may respond atypically to the social overtures of other people.
  • People with Level 1 ASD may appear to have decreased interest in social interactions, and their attempts to make friends may appear odd and may typically be unsuccessful.
  • They may speak in full sentences.
  • People with Level 1 ASD might be firm and inflexible and subsequently experience difficulties in functioning as a result. They may experience difficulty switching between activities.
  • They might experience difficulty with planning and organization that may hinder their ability to be independent. 

With any ASD diagnosis, including Level 1, the possible combinations of traits, strengths, and challenges are almost endless. This not only makes the characterization of behaviors difficult but also can leave you confused as to what kind and level of support is needed.

Determining Support Needs

Autistic people labeled as being high-functioning may excel in school or be very skilled at their job, but may have difficulty completing hygiene tasks, like showering and brushing, on a daily basis. A "high-functioning" skilled professional may have severe sensory sensitivites, anxiety, and perseveration and might actually have a more difficult time in the workplace than an individual labelled as "low-functioning" who has less anxiety and fewer sensory issues.

What's more, a "low-functioning" autistic person might spend most of their day in a supported setting where the possibility of dangerous interactions is almost zero. Meanwhile, the "high-functioning" individual may need to navigate a world full of complex and hazardous situations.

High-functioning autistic people often need many supports, but might not need another person to facilitate those supports. They may need to keep disposable, travel toothbrushes at their bedside rather than needing someone to brush their teeth for them. They might need reminders/alarms to remember to eat and primarily eat foods that are quick and easy to make, but may not need to be hand-fed. The cost and time associated with creating these secondary support systems, often alone, is a burden not oft talked about.

While it may be easy to think that autistic people labelled as being high-functioning need less support, they are actually just faced with different challenges. They may have academic success and marketable skills, but may deal with emotional dysregulation (and the associated depression and anxiety), inconsistent hygiene practices, and the symptoms of masking and autistic burnout.

Navigating a Neurotypical World

The ever-changing definitions of autism can lead to a lack of clarity. Technology and cultural change are also modifying social expectations. In the past, face-to-face communication was what neurotypical society saw as the key to personal success for an autistic person; today, many autistic people can interact with others online, make friends through social media, and even hold down remote jobs. These built-in forms of support have enabled more autistic people to thrive in a neurotypical society.

Some businesses like Google are giving autistic workers a chance, while others are not yet doing that work. Even in spaces where marginalized people are specifically recruited, they may not have the infrastructural and work-cultural support they need to survive or thrive.

3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Neggers YH. Increasing prevalence, changes in diagnostic criteria, and nutritional risk factors for autism spectrum disorders. ISRN Nutr. 2014;2014:514026. doi: 10.1155/2014/514026

  2. American Psychiatric Association (APA). Diagnostic and Statistical Manual of Mental Disorders, 5th Edition: DSM-5. Philadelphia, PA: APA; 2013.

  3. Chen JL, Leader G, Sung C, et al. Trends in employment for individuals with autism spectrum disorder: A review of the research literature. Rev J Autism Dev Disord. 2015;2:115. doi:10.1007/s40489-014-0041-6

By Lisa Jo Rudy
Lisa Jo Rudy, MDiv, is a writer, advocate, author, and consultant specializing in the field of autism.