ADHD Symptoms in Children: Signs UK Parents Should Know

ADHD in children is much more than a child who can’t sit still. Inattentive ADHD — particularly in girls — often goes completely undetected throughout primary school, only becoming apparent when demands increase. This guide helps parents recognise the full range of ADHD presentations in children.

Common ADHD Symptoms in Children (Primary School Age)

Inattentive Symptoms

Easily distracted — losing focus mid-task, going off on tangents
Forgetting instructions almost immediately after being given them
Losing school equipment, PE kit, homework constantly
Difficulty finishing schoolwork — not from inability but from difficulty sustaining effort
Appearing not to listen — ‘in a world of their own’
Making careless errors in work — rushing, not checking
Avoiding tasks that require sustained mental effort

Hyperactive and Impulsive Symptoms

Difficulty sitting still — fidgeting, squirming, getting up from seat
Excessive running, climbing or physical movement in inappropriate situations
Difficulty playing quietly
Talking excessively, interrupting, blurting out
Difficulty waiting their turn — queue jumping, calling out in class
Acting without thinking — accidents, impulsive decisions, saying hurtful things

ADHD Symptoms in Secondary School Age and Teenagers

ADHD often becomes more apparent — or is first recognised — when children move to secondary school and the organisational demands increase sharply:

Struggling to keep track of multiple subjects, teachers, homework deadlines
Forgetting to write down homework, then forgetting to do it
Significant underperformance relative to evident intelligence
Emotional difficulties — more intense than peers, falling out with friends repeatedly
Screen time and gaming becoming an escape from the constant frustration of school
Anxiety developing as a secondary condition from years of feeling ‘wrong’

ADHD in Girls — The Hidden Presentation

Girls with ADHD are significantly more likely to have the inattentive type and to mask their difficulties through social imitation, people-pleasing and enormous compensatory effort. Common presentations include:

Described as ‘dreamy’, ‘ditzy’ or ‘tries hard but doesn’t reach her potential’
Works extremely hard to produce average results — far more effort than peers
Very chatty and social — masking inattention through social engagement
Intense emotional reactions described as ‘too sensitive’ or ‘dramatic’
Struggles at home but holds it together at school — ‘school mask’
Anxiety and perfectionism as compensatory strategies

Teachers and GPs sometimes say ‘she can’t have ADHD, she’s too well-behaved at school’ or ‘she focuses fine on things she enjoys.’ These are not reasons to rule out ADHD — they are common presentations of inattentive ADHD in girls.

When Should I Get My Child Assessed?

Consider seeking a private ADHD assessment for your child if:

Symptoms have been present for at least 6 months and across multiple settings (home and school)
They are significantly impacting school performance, friendships or family life
Your GP or school has suggested it, or the NHS waiting list is too long
Your child is distressed by their difficulties and needs answers

Ready to find an ADHD assessor near you?

Compare qualified private ADHD assessment providers in your area — free, no obligation, and we send you a free guide instantly.

Frequently Asked Questions

What age can a child be diagnosed with ADHD?

ADHD can be diagnosed from age 3, though most assessments are conducted from age 5–6 onwards when the demands of school reveal difficulties more clearly. There is no upper age limit — ADHD can be diagnosed at any age.

Will my child’s school accept a private ADHD diagnosis?

Yes. Schools are required to make reasonable adjustments under the Equality Act 2010 and the SEND Code of Practice regardless of whether the diagnosis is NHS or private. The formal written diagnostic report from a qualified specialist is the required evidence. For exam concessions and EHCP applications, private reports are fully valid.

How is ADHD different in girls than in boys?

Girls with ADHD are more likely to have the inattentive type, which presents quietly without obvious hyperactivity. They are more likely to mask their difficulties, develop secondary anxiety, and be described as dreamy or emotionally sensitive rather than disruptive. This means ADHD in girls is frequently missed or diagnosed much later than in boys.

Important: Information on this site is for general purposes only and does not constitute medical advice. Always consult a qualified healthcare professional. Assessment details correct at time of publication (May 2026). ADHD Assessment UK may receive a referral fee from providers listed.

ADHD Assessment UK editorial team