Autism is often diagnosed between ages 2 and 4, though early signs may be noticeable sooner. Early identification can help families access support and understand needs at home, nursery, and school.

Common signs in children

1. Social communication challenges
   • limited or absent eye contact
   • difficulty responding to their name or recognising others’ emotions
   • limited interest in playing with others
   • delayed or absent speech, or differences in verbal/non-verbal communication
2. Repetitive behaviours and restricted interests
   • repetitive movements or sounds (e.g., hand-flapping, repeating phrases)
   • intense focus on particular objects or topics
   • distress when routines or environments change
3. Sensory sensitivities
   • strong reactions to sounds, lights, textures, or smells
   • seeking or avoiding sensory experiences (e.g., spinning, touching, covering ears)

How diagnosis usually works

• Parental concerns: families report early signs and developmental differences
• Screening: some services use tools such as M-CHAT to identify possible autism traits
• Multidisciplinary assessment: professionals may include paediatricians, psychologists, SALT and OT
• Information gathering: observations + parent and nursery/school information

If you’re worried, keep a few clear examples of what you notice at home and what nursery/school are seeing too.

Autism can become more noticeable in adolescence as friendship expectations, independence, and school pressures increase. Some young people may have been coping for years before difficulties become obvious.

Common signs in young people

1. Social interaction difficulties
   • difficulty making or keeping friendships due to misunderstandings of social cues
   • challenges with conversation (turn-taking, humour, sarcasm, figurative language)
   • preference for solitary activities or one close friendship rather than groups
2. Intense interests
   • deep focus on specific topics or activities
   • high knowledge in a particular area (often a strength)
3. Emotional regulation and daily life
   • anxiety, shutdown, or meltdowns (often linked to stress/overload)
   • distress with changes in routine
   • organisation, time management, and task completion difficulties

How diagnosis usually works

• Development history: early milestones and long-term patterns
• Young person’s voice: their lived experience and self-report where possible
• Education input: school evidence can be very helpful
• Psychological assessment: observation + structured interviews and questionnaires

Tip: school can support with evidence even before diagnosis (reasonable adjustments/SEN support).

Many adults seek an autism diagnosis after years of feeling different, struggling with sensory overload, or finding social and workplace demands exhausting. Some people have strong coping strategies (sometimes called masking), which can delay diagnosis.

Common signs in adults

1. Social interaction difficulties
   • finding friendships hard to start or maintain
   • avoiding social situations due to stress or uncertainty
   • difficulty reading non-verbal communication (tone, facial expressions)
2. Repetitive behaviours and rigidity
   • strong need for routine and difficulty with changes
   • repetitive actions or rituals that help regulate stress
   • preference for familiar activities and environments
3. Sensory sensitivities
   • sensitivity to noise, lighting, smells, textures, crowds
   • seeking calm/low-stimulation spaces to cope

How diagnosis usually works

• Questionnaires: some services use tools such as the Autism Spectrum Quotient (AQ)
• Clinical interviews: discussion about childhood, relationships, sensory needs, routines and coping
• Observation/assessment: structured tools and professional judgement
• Life history: information from family or records can help (if available)

Many adults find diagnosis helpful for self-understanding and for accessing workplace adjustments and support.

Screening tools can help identify whether autism traits may be present, but they do not provide a diagnosis. They’re best used as a starting point for conversations with professionals.

Examples

• M-CHAT: often used for toddlers to identify possible autism traits
• AQ: a self-report tool sometimes used with adults
• School/setting questionnaires: may be used to support referrals

If a tool suggests autistic traits, the next step is usually speaking to your GP (adults) or health visitor/GP (children).

Whether it’s for a child, young person or adult, preparation can make the process feel clearer and less stressful. The most helpful evidence is specific, real examples of day-to-day impact.

What to gather

• Examples: 5–10 short examples (sensory, routines, communication, friendships, daily living)
• Education evidence: SEN notes, reports, behaviour logs, attendance concerns
• Health evidence: GP letters, CAMHS notes, SALT/OT notes (if relevant)
• Timeline: key points from early years to now (what changed, what helped)

Helpful prompts

• What happens in noisy/busy places?
• What happens when plans change?
• How does the person communicate needs and feelings?
• What support is needed at home/school/work?

Tip: describe impact across settings (home + school/work) where possible.