ADHD symptoms

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental condition that affects how people focus, manage their impulses and regulate their energy levels. It’s estimated to affect around 5% of children and 3% to 4% of adults in the UK, although many cases go undiagnosed.

ADHD is typically characterised by symptoms in three main areas:

1. Inattention (such as difficulty concentrating or staying organised)
2. Hyperactivity (excessive restlessness or difficulty straying still)
3. Impulsivity (acting or speaking without thinking)

These symptoms can show up in different ways depending on various factors, such as your age, gender environment, experiences and way of coping. In some people – especially people who have developed coping mechanisms – the signs may be subtle or misunderstood.

This page explores the common signs of ADHD in both children and adults, helping you understand how it can appear in everyday life.

At what age do symptoms present?

ADHD is a neurodevelopmental condition, which means that people are born with it, whether it is diagnosed or not.

ADHD traits are usually noticed in childhood, often before the age of 12. For some, the signs show up early, especially in active children who struggle to sit still, follow instructions or stay focused at school.

For others, the signs may be harder to spot. You may not have received a diagnosis as a child, even if the symptoms were there. Many people only recognise they have ADHD in adulthood, after years of finding certain aspects of life more challenging.

This can be due to factors such as:

• Girls and women may present with less obvious or less overt symptoms – such as daydreaming, forgetfulness or difficulty concentrating – which may be misinterpreted as shyness, low confidence or anxiety.
• Children in structured and supportive environments, such as stable homes or nurturing schools, may learn to mask or compensate for their difficulties. Symptoms often become more noticeable when they move into more demanding environments with less support

In many cases, signs of ADHD may become more noticeable during life transitions, such as starting secondary school, going to university, entering the workplace or managing adult responsibilities. The increased responsibility of these changes can stretch someone’s ability to cope, making underlying symptoms more challenging to manage and easier to spot.

How ADHD traits show up in daily life

Recognising ADHD isn’t always about spotting dramatic signs – often, it’s the small, persistent struggles that stand out. Things like losing your keys (again), missing deadlines, or finding it hard to switch off at night. These everyday challenges can affect your confidence and overall wellbeing.

Here are some of the most common ways ADHD can impact everyday life.

In children

ADHD symptoms in children often show up at home, school or in social situations. Behaviours may be misread as laziness, defiance or overexcitement – when in reality, they’re part of how the child’s brain processes the world.

Common examples include:

• Struggling to finish homework or follow instructions – they may lose track halfway through or become overwhelmed by multiple steps
• Frequently forgetting or losing items like lunchboxes, jumpers or books
• Finding it hard to sit still or stay quiet in class – even when they’re trying their best to behave
• Blurting out answers or interrupting conversations
• Getting upset or angry very quickly, even over small problems
• Being chronically late or disorganised – for example, getting distracted when getting ready
• Struggling to fall asleep or stay asleep

In adults

For adults, ADHD symptoms often show up in more subtle – but still impactful – ways. Many adults only begin to question whether they have ADHD when life becomes busier or more demanding.

You might experience:

• Frequently losing keys, phones or important documents – despite your best efforts to stay organised
• Starting projects with enthusiasm but struggling to finish
• Feeling constantly rushed, late or behind – often underestimating how long things take (known as ‘time blindness’)
• Difficulty relaxing or switching of, even during downtime
• Strong emotional reactions – becoming easily frustrated, overwhelmed or tearful in situations others might find manageable
• Talking over others or jumping between topics in conversation
• Poor sleep patterns – including difficulty falling asleep, restless legs or racing thoughts

Co-occurring conditions

ADHD often exists alongside other mental health or neurodevelopmental conditions. Sometimes, another condition is diagnosed first or masks ADHD symptoms, making them harder to spot. That’s why a full professional assessment is important to understand the whole picture and get the right support. 

The following conditions can co-occur with ADHD, but some symptoms may also overlap, which can make it harder to tell them apart:

• Anxiety – worry, overthinking, restlessness and difficulty concentrating
• Depression – low mood, lack of energy, forgetfulness and trouble staying motivated
• Autism – social differences, sensory sensitivities and a strong need for routine
• Obsessive compulsive disorder (OCD) – intrusive thoughts and rigid behaviours that may resemble anxiety or restlessness
• Trauma-related conditions – including post-traumatic stress disorder (PTSD) and complex PTSD (CPTSD), which can involve emotional overwhelm, hypervigilance and difficulty concentrating. Trauma may also make ADHD traits feel more intense or harder to manage
• Learning difficulties – such as dyslexia, which can affect reading, spelling or processing speed

Many of these share symptoms with ADHD, like inattention and emotional dysregulation, which can make it difficult to assess accurately. A formal ADHD assessment can help distinguish these overlaps and ensure you get support that truly fits your needs.