How to Know If My Child Has ADHD: Signs by Age

Restless, distracted or explosive? A child psychologist in Valencia explains the real signs of ADHD by age and when to assess.

Constantly on the move, distracted in class or exploding at the smallest thing? Here are the real signs of ADHD by age and when to assess.

"He just can't sit still." "He starts a thousand things and finishes none." "In class he zones out and the teacher doesn't know what to do anymore." "At home, the smallest setback turns into an explosion of anger."

If you've been hearing these phrases about your child for months (or years), the word **ADHD** has probably crossed your mind. And with it the doubt: *"Is something really going on, or is he just an active child?"*

As a General Health Psychologist specialised in child and adolescent care (Reg. No. CV16625), let me confirm something important: ADHD (Attention-Deficit/Hyperactivity Disorder) **is not a whim of modern parenting nor an invention of pharmaceutical companies.** It is one of the best-documented neurodevelopmental disorders that exists, with clear neurobiological foundations described in the DSM-5-TR and ICD-11.

But it's also true that **not every active child has ADHD**, nor does every distracted one. In this article you'll learn to tell apart the real signs of ADHD by your child's age, and to decide with clinical criteria whether a professional [psychological assessment](/servicios/evaluaciones-psicologicas) is advisable.

What ADHD Really Is (and What It Is Not)

ADHD is a **neurodevelopmental disorder** that affects three major areas: sustained attention, impulse control and, in many cases, motor activity levels. Its origin is neurobiological: the brain of a child with ADHD functions with lower levels of dopamine and noradrenaline in the regions responsible for self-control (prefrontal cortex).

This means your child **doesn't get distracted because they want to**, **doesn't interrupt out of rudeness** and **doesn't explode because you've spoiled them**. Their brain literally takes longer to mature the executive functions (planning, organisation, inhibition) than that of a neurotypical child.

There are three clinical presentations:

- **Predominantly inattentive** (the most invisible, frequent in girls): they daydream, drift off, lose things, forget tasks. They don't disturb the class, which is why the diagnosis often arrives late.

- **Predominantly hyperactive-impulsive**: they can't sit still, talk non-stop, act before thinking.

- **Combined**: the most commonly diagnosed, mixing both.

Signs by Age: What the Textbooks Don't Always Tell You

ADHD doesn't look the same at 4 as it does at 15. These are the signs that, in clinical practice, best guide us at each stage.

Ages 3 to 6: the "impossible to tire" child

- Climbs on everything, doesn't gauge danger, has fallen more times than all their siblings put together.

- At the park they run non-stop; at home they move from activity to activity without finishing any.

- They are **unable to wait their turn** (in games, in queues, in conversations).

- They have [much more intense and longer tantrums](/blog/rabietas-ninos-cuando-preocuparse) than other children their age, and frustration overwhelms them easily.

- At nursery, the teacher repeats that "he doesn't concentrate at circle time" or that "he bothers the other children".

At this age **it's still early for a closed diagnosis** (DSM-5-TR normally requires waiting until age 6-7), but we can start a screening assessment and work on prevention.

Ages 7 to 12: when school exposes everything

This is the age when most diagnoses are made, because academic demands lay bare the difficulties:

- They take **three hours to do what other children do in thirty minutes**, not for lack of ability, but because they get distracted by any noise, their own thoughts or a pen.

- They forget to write down homework, lose their pencil case, leave their PE kit at school over and over again.

- Their exams are full of "silly" mistakes: they don't read the question properly, leave questions blank, don't check.

- In class, **they interrupt, blurt out answers or get up from their seat.**

- At home, any change of plan makes them explode, and homework time is a daily battlefield.

- They start to have problems with friends because of their impulsivity (touching without permission, not waiting their turn, saying things without a filter).

It's very common at this stage for ADHD to coexist with [childhood anxiety](/blog/ansiedad-infantil-senales-sintomas), low self-esteem ("I'm stupid", "I do everything wrong") or [learning difficulties](/servicios/dificultades-aprendizaje) such as dyslexia.

In teenagers (13-17): hyperactivity fades, but the internal chaos stays

This is one of the great myths: *"now that he doesn't move so much, he must have outgrown it"*. False. Motor hyperactivity usually fades, but executive problems persist and become even more limiting:

- Chronic procrastination: leaves everything to the last day, fails subjects by not handing in coursework they knew how to do.

- Extreme disorganisation: chaotic diary, unliveable bedroom, phone with 60 tabs open.

- **Internal feeling of "being revved up inside"** even though they look calm on the outside.

- Impulsivity in decisions (purchases, social media, driving once they reach the age, substance use).

- Intense mood swings, low frustration tolerance and, very frequently, [screen addiction](/blog/adiccion-pantallas-ninos-adolescentes) (video games or TikTok give them the dopamine hit their brain demands).

- Self-esteem badly damaged after years of "you could do better if you tried harder".

What Is NOT Necessarily ADHD

Before jumping to a diagnosis, it's worth ruling out other causes that can look like ADHD but aren't:

- Children with [high abilities / giftedness](/servicios/altas-capacidades) bored in class (they look inattentive because the pace is too slow for them).

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