What we mean by signs
Autism presents differently in different people. There is no single way to appear or be autistic because all autistic people are unique, and for this reason there is no definitive sign or list of signs that can tell you whether you, your child or another person is autistic.
This page includes a wide range of common signs that people have noticed in autistic children and adults. However, not every autistic person will show every sign. Autism is assessed by clinicians who gather information on multiple signs that must align with the core characteristics of autism in order for a diagnosis to be made. (You can find out more about this on our page Criteria and tools used for an autism assessment.)
Why can it be helpful to think about signs?
The only reliable way to find out whether someone is autistic is through an autism assessment. However, before deciding whether to pursue a diagnosis, or waiting for an assessment, it can be helpful to consider the signs you have noticed. For example:
- it may be useful to show a list of signs to a GP or another health care professional if you want to discuss a referral for an autism assessment with them, or as evidence to prepare for your assessment
- you may wish to talk to family, friends, partners or colleagues about what you have noticed
- if you think someone else is autistic and want to discuss this with them, it may be helpful to discuss the signs you have noticed
- you may wish to bring it up with a school, Further or Higher education institution, or at work, particularly to request support before seeking a diagnosis (a process that can take a long time).
Autistic people and families often describe a gradual process of ‘light bulb’ or ‘aha’ moments – noticing signs that led to them to consider whether they, their child or someone else might be autistic.
How do signs relate to the core characteristics of autism?
Autism is defined by ‘core characteristics’. These are described in medical literature as:
- social communication and social interaction differences
- restricted and repetitive behaviours and interests (RRBIs) – including potential sensory differences.
For more information about the core characteristics of autism, visit our page What is autism?
The core characteristics of autism must be present for a diagnosis to be made. However, before an autism assessment, people commonly notice the presence of certain signs in themselves or in others (children or adults) that may suggest they could be autistic.
The signs that are noticed are usually consistent with the core characteristics of autism. However, it can be difficult to make this connection if you are not already familiar with autism. Stereotypes about autism can mean that it isn’t always easy to spot the signs of autism in someone who doesn’t fit the stereotype.
Autistic people and their families have highlighted that spotting the signs of autism through the lens of the core characteristics (and diagnostic criteria) can be complicated for several reasons, including because:
- they are based on what other people can see and their interpretations of behaviour, which autistic people may not feel describes their experience
- they are written in medical language that can be hard to understand
- people can misinterpret signs of autism as signs of something else, such as bad behaviour, academic giftedness or mental illness
- they don’t account for masking, where a person hides or suppresses their natural autistic characteristics
- they may not capture the co-occurrence of related conditions (for example, ADHD).
Signs related to the core characteristics
Social interaction and communication
A core characteristic of autism is social interaction and communication differences. Examples of signs that relate to this core characteristic include:
- limited, delayed, or no speech (including loss of language sometime after learning to speak and avoidance of talking, despite being able to)
- using repeated words and phrases (echolalia), made-up words, technical or very literal speech, pauses, and sophisticated or advanced language
- speaking in an unusual accent
- differences in rate of speech (fast/slow) and intonation (monotone/varied)
- using fewer gestures or facial expressions to communicate
- preferring not to make eye-contact or finding this uncomfortable
- finding it difficult to recognise or read body language or facial expressions
- finding it hard to judge pauses, turn-taking, or to be interrupted during conversations
- being confused by metaphors and idioms, not always understanding hidden meanings or inference and taking phrases literally
- not engaging in a two-way conversation (for example, not asking other people questions about themselves)
- mismatching non-verbal and verbal communication (for example, saying they are feeling an emotion, but with body language that doesn't appear to align with that emotion)
- seems less aware of others around them – for example, they might not respond to their name being called
- autistic babies and toddlers may not smile when smiled at by others or point when they want to show others something or find something interesting
- find following ‘social rules’ confusing
- talking in depth about their own interests, but not engaging in others’ interests
- being direct and honest in communicating opinions (often more direct and honest than people expect; for example, saying they don’t like something when they might have been expected to tell a 'polite' lie)
- difficulty telling the difference between someone being friendly or joking and someone trying to bully or hurt their feelings
- difficulty imagining experiences they have never had
- having a clear idea of right and wrong, and a strong sense of justice, but may struggle with grey areas or unclear rules.
Restricted and repetitive behaviours and interests (RRBIs)
A core characteristic of autism is restricted and repetitive behaviours and interests (RRBIs). Many autistic people prefer to call these ‘self-soothing’ or ‘self-regulating’ activities. Examples of signs that relate to this core characteristic include:
- a strong preference for routine
- distress when a routine changes
- enjoying order and benefiting from clearly defined rules
- making repetitive movements when excited or upset, for example flapping hands, or making the same noise repeatedly
- using repetitive behaviours as a way of staying calm
- having strong passions and dedicated interests (sometimes known as ‘special interests’) for specific subjects/hobbies, that you/they can engage with intensely
- find engaging in their passions and dedicated interests calming and soothing
- finding it easy to focus on specific interests, but also find it difficult to disengage and move on to other tasks.
Sensory differences
Sensory differences are considered part of the core characteristic restricted and repetitive behaviours and interests (RRBIs), because the sensory difference may be expressed in sensory seeking or sensory avoidant behaviour that may appear restricted and/or repetitive.
Examples of signs that relate to sensory differences include:
- being much more or much less sensitive to visual stimuli, sounds, smells or touch than other people
- seeking out sensory inputs, including visuals, sounds, smells or tactile stimuli and using them as a comfort
- showing strong distress, aversion or actively avoiding sources of sensory difficulty
- finding certain sounds, smells, feelings or foods particularly calming or enjoyable, such as coloured lights or being tucked tightly into bed.
Anxiety and distressed behaviour signs
All the signs listed in the sections above can potentially lead to high levels of anxiety and may result in:
- distressed behaviour that may present as aggression (towards yourself/themselves or others)
- overwhelm and/or meltdowns – potentially from masking in social situations and needing to release the stress of doing so after returning to a ‘safe space’
- difficulties in school/workplace
- appearing withdrawn or finding it difficult to engage with when recovering from social situations (sometimes known as ‘shutdown)’
- being misunderstood by others
- reaching a point of breakdown, severe mental health difficulties or burnout.
Other signs that a person may be autistic
Many autistic people report feeling different from other people of the same or similar age. These are some of the ways they may feel different:
- struggling with things that peers don’t (for example, socialising or daily tasks)
- experiencing things differently from peers
- feeling like an 'alien' and/or they don't fit in with other people
- having to put effort into behaviours that others seem to do automatically (for example, forcing yourself/themselves to make eye contact)
- completing tasks in unusual or creative ways
- using coping strategies to make it through the day
- being excluded, bullied, or not fitting in with others
- finding it difficult to have meaningful relationships with people
- finding it more difficult than most to answer interview questions, write CVs/applications and find employment.
Making sense of things
Autistic people often feel they can’t make sense of certain situations or themselves. This can include:
- feeling they don’t understand how the world works
- not understanding the purpose of some typical social events
- not understanding their own identity or knowing who they are (this may be due to masking)
- confusion when there is a lack of structure.
A sense of being overwhelmed
A feeling shared by some autistic people is that of being overwhelmed, which can mean everyday tasks can become challenging. This sense of being overwhelmed may include:
- feeling overwhelmed by anxiety or anger and having difficulty keeping calm in stressful situations
- experiencing distress or panic
- having difficulty transitioning between classes, schools and further education
- having difficulty engaging with school or being unable to attend school full time
- having difficulty remaining in employment due to problems maintaining relationships with colleagues and managers or because some workplaces or offices can be overwhelming environments
- struggling with self-harm or suicidal ideation
- feeling lonely and isolated
- struggling with everyday tasks, such as cooking, cleaning, self-care, finances and life admin.
Being misunderstood by others
Other people may also appear to misunderstand autistic people. Indications of being misunderstood include:
- being regarded as a ‘difficult’ student or employee because you/they do not comply with others’ requests or have difficulty engaging
- underachieving in education or in employment compared to what you/they appear to be capable of
- unable to achieve qualifications from school or in Further or Higher education
- being labelled as gifted, sensitive or shy
- mental health diagnoses don’t fully explain your/their experiences
- mental health services/treatment have been ineffective.
Recognising the signs that a child or young person may be autistic
Parents or carers are often the first to notice the signs that their child or young person may be autistic, but it can also be other family members, friends, or education and health professionals.
You may notice that your child:
- responds differently than other children (for example, responding to their name; responding to sensory stimuli such as light, sound, taste and touch)
- doesn’t engage with other children
- has additional characteristics (for example, hyperactivity) that were investigated
- loses a skill they once had (for example, loss of speech that had previously developed)
- experiences challenges in school
- has mental health issues.
Additionally, parents may recognise their family and child’s experience reflected in media about autism (such as books and YouTube videos).
Be aware that not all information and media about autism is reliable and evidence based. You should be particularly wary of any source that talks about how to ‘cure’ or ‘treat’ autism, which is not possible and so the source is likely to be unreliable. Read more about this issue on our Strategies and interventions page.
