What are 9 Symptoms of ADHD? Signs in Adults and Children

Estimated reading time: 5 minutes

• Quick overview: Why nine symptoms?
• The 9 core ADHD symptoms (grouped)
  • Inattention
  • Hyperactivity
  • Impulsivity
• What are the main signs of ADHD in children?
• What are the symptoms of ADHD in adults?
• How do ADHD symptoms affect daily life?
• Can ADHD symptoms overlap with other conditions?
• When should you seek professional help for ADHD?
• Next steps and treatment options
• Key takeaways

Quick overview: What are 9 symptoms of ADHD?

Clinicians and guides often distill ADHD into practical signs that people and families can recognise. Listing 9 common symptoms helps capture how ADHD affects thinking, behaviour, and daily functioning across ages without getting lost in long diagnostic lists.

The 9 core symptoms of ADHD (grouped)

Note: these descriptions are for awareness. A formal diagnosis requires professional assessment.

Inattention

1) Difficulty sustaining attention

• Children: loses interest in tasks quickly, daydreams in class, struggles to finish homework. Example: starts reading a story but drifts off before the end.
• Adults: finds long meetings or detailed paperwork exhausting, often forgets to follow through on projects. Example: starts an email then gets sidetracked by another browser tab and never finishes.

2) Poor organisation and task management

• Children: messy backpack or desk, trouble planning assignments, misses deadlines.
• Adults: missed appointments, chaotic to-do lists, difficulty prioritising work. Example: repeatedly underestimates how long tasks will take and misses key steps.

3) Frequent forgetfulness and losing things

• Children: loses schoolbooks, toys; forgets lunchboxes or PE kits.
• Adults: misplaces keys, misses payment deadlines, forgets names or appointments. Example: leaving the house without a wallet or phone.

Hyperactivity

4) Excessive movement or restlessness

• Children: fidgets, runs or climbs inappropriately, cannot sit still for long.
• Adults: internal restlessness, paces, taps fingers, or feels unable to relax. Example: repeatedly getting up during meetings or needing physical activity to feel calm.

5) Difficulty playing or working quietly

• Children: noisy when expected to be quiet, disrupts group activities.
• Adults: speaks loudly, struggles to modulate energy, may dominate conversations. Example: speaking over colleagues without realising volume or timing.

6) High levels of activity or talkativeness

• Children: talks excessively, interrupts games, eager to engage constantly.
• Adults: rapid speech, juggling many projects at once, becomes overwhelmed by too many commitments. Example: signing up for multiple social or work projects and struggling to complete them.

Impulsivity

7) Acting without thinking

• Children: grabs toys from others, makes risky choices on the playground.
• Adults: impulsive spending, risky driving decisions, blurting out personal details. Example: buying expensive items on impulse.

8) Difficulty waiting or taking turns

• Children: impatience in lines or group activities, difficulty waiting for a turn in games.
• Adults: interrupts conversations, impatient in queues or meetings. Example: cutting in during a group discussion or pressing to make decisions prematurely.

9) Interrupting or intruding on others

• Children: butts into games, answers questions before the teacher finishes.
• Adults: interrupts colleagues, finishes others’ sentences, or contacts people at inappropriate times. Example: calling late at night with immediate demands.

What are the main signs of ADHD in children?

The main signs in children often show up as school and social difficulties: inconsistent academic performance, trouble following instructions, impulsive behaviour, and strained peer relationships. Teachers or caregivers may notice patterns like frequent distraction, messy work, excessive fidgeting, or repeated warnings about behaviour.

What are the symptoms of ADHD in adults?

In adults, ADHD symptoms often present as chronic disorganisation, time management problems, relationship strain, and difficulties sustaining employment or study. Adults may develop coping strategies that mask symptoms, so ADHD can be missed for years. Emotional dysregulation — such as quick frustration or mood swings — can also be prominent.

How do ADHD symptoms affect daily life?

ADHD can impact many areas:

• Work and study: missed deadlines, inconsistent productivity, poor concentration at critical moments.
• Home life: unpaid bills, clutter, forgotten appointments, stress in relationships.
• Social interactions: interrupting others, impatience, or behaviour that friends and family find puzzling or hurtful.
• Safety and health: impulsive decisions like risky driving, or forgetting medication schedules.

Real-life example: someone with inattentive ADHD might be highly skilled in their role but miss promotion opportunities because management interprets missed deadlines as lack of commitment rather than a symptom.

Can ADHD symptoms overlap with other conditions?

Yes. Many conditions share features with ADHD, which can make self-identification difficult. Common overlaps include:

• Anxiety disorders and depression: both can cause poor concentration, restlessness, and sleep disruption.
• Autism spectrum conditions: challenges with attention and social interaction may be present in both.
• Sleep disorders: poor sleep can mimic inattention and irritability.
• Learning differences (eg dyslexia): can cause academic struggles that look like inattention.

Because of these overlaps, assessment should look at the whole picture, including onset, context, and whether symptoms are pervasive across settings.

For more background on ADHD in adults, the NHS provides a helpful overview and guidance on next steps. NHS ADHD adults guide

When should you seek professional help for ADHD?

Consider professional help if:

• Symptoms are persistent and affect daily functioning at home, school, or work.
• Strategies you’ve tried (organisational tools, routines) don’t provide enough relief.
• You notice repeated consequences such as job loss, relationship breakdowns, or academic failure.

A clinician will take a full history, often using structured screening tools and reports from family or teachers. If you want to start with a simple check, try an online screening test to see if your experiences align with common ADHD traits. Neurodirect’s online ADHD tests offers several free options, including ASRS-based tests, to help you identify next steps.

For detailed clinical information, this Cleveland Clinic page is a reliable resource on ADHD symptoms and treatment options. Cleveland Clinic ADHD overview

Next steps and treatment options

If screening suggests ADHD, a professional assessment can confirm a diagnosis and discuss tailored treatment. Management often includes:

• Psychoeducation and skills coaching (time management, organisational strategies)
• Psychotherapy such as CBT adapted for ADHD
• Medication when appropriate, under medical supervision
• Workplace or educational adjustments

Combining approaches gives the best chance of reducing symptoms and improving daily functioning.

Key takeaways

• The nine symptoms listed above cover common signs across inattention, hyperactivity, and impulsivity.
• ADHD presents differently in children and adults; context matters.
• Symptoms commonly overlap with other conditions, so professional assessment is important.
• Practical help is available, and assessments usually start with screening followed by a full clinical evaluation.

If you suspect ADHD in yourself or a loved one, a helpful first step is a screening test. You can try Neurodirect’s free online ADHD tests, including ASRS-based tools that are quick and informative.

Take our free ADHD test online and learn if your symptoms align with ADHD traits.