ADHD, the Body, and the Nervous System: Exploring Emerging Links with Inflammation and Dysautonomia
- taniaslt
- Jan 20
- 6 min read
Attention Deficit Hyperactivity Disorder (ADHD) is often seen as a condition that primarily affects the brain, focusing on attention, impulsivity, and hyperactivity. Yet, emerging research suggests that ADHD may involve more than just cognitive and behavioural symptoms. Physical health factors such as inflammation, joint issues, and autonomic nervous system dysfunction appear to play a role in how ADHD presents and affects daily life. Understanding ADHD through a whole-body lens can open new paths for assessment, support, and treatment.
Understanding ADHD Through a Whole-Body Lens
ADHD has traditionally been studied as a neurodevelopmental disorder focused on brain function. However, many individuals with ADHD report physical symptoms that do not fit neatly into this framework. These include chronic pain, digestive issues, and autonomic symptoms like dizziness or heart rate irregularities. This has led researchers to explore how the brain and body interact in ADHD.
The brain and body communicate constantly through the nervous system, immune system, and hormonal pathways. Disruptions in these systems may influence attention, mood, and behaviour. Viewing ADHD as a condition that involves both brain and body can help explain some of the variability in symptoms and treatment responses.
ADHD and Chronic Inflammation: What Do We Know So Far?
Chronic inflammation is the body's prolonged immune response that can affect multiple organs and systems. Some studies suggest that people with ADHD may have higher levels of inflammatory markers in their blood. This inflammation could influence brain function by affecting neurotransmitter systems or brain development.
For example, elevated cytokines, which are proteins involved in inflammation, have been found in some individuals with ADHD. These molecules can cross the blood-brain barrier and potentially alter brain signalling. While the exact relationship between inflammation and ADHD symptoms is still unclear, it raises the possibility that managing inflammation might improve some ADHD-related difficulties.
Why Joint Hypermobility Matters in ADHD
Joint hypermobility means having unusually flexible joints that move beyond the normal range. It is more common in people with ADHD than in the general population. This condition can cause joint pain, fatigue, and coordination problems, which may worsen attention and emotional regulation.
Research suggests that around half of people with ADHD show signs of hypermobility. While many individuals are asymptomatic, others develop more complex conditions such as:
Hypermobility Spectrum Disorder (HSD)
Hypermobile Ehlers-Danlos syndrome (hEDS)
These conditions can affect joints, skin, blood vessels, and the gastrointestinal system, and are strongly associated with both inflammation and autonomic nervous system differences.
Hypermobility-related conditions are also frequently linked with:
Chronic pain and fatigue
Gastrointestinal difficulties
Autonomic symptoms such as dizziness and palpitations
Heightened anxiety and sensory sensitivity
For many individuals, these physical experiences significantly affect daily functioning and wellbeing—yet they are often misunderstood or misattributed to anxiety alone.
Recognising hypermobility in ADHD patients can guide more tailored physical therapies and lifestyle adjustments.
Mast Cell Activation Syndrome (MCAS): An Emerging Area of Research
Mast cells are immune cells that release chemicals during allergic reactions and inflammation. Mast Cell Activation Syndrome (MCAS) occurs when these cells release excessive amounts of these chemicals, causing symptoms like flushing, itching, gastrointestinal distress, and brain fog.
When mast cells become over-reactive, they may release excessive inflammatory chemicals in response to triggers such as:
Foods, medications, or alcohol
Infections
Hormonal changes
Heat, cold, or physical stress
Emotional stress
Environmental toxins
This can result in multi-system symptoms, including:
Flushing, itching, hives
Abdominal pain, nausea, diarrhoea
Rapid heart rate or low blood pressure
Fatigue and brain fog
Anxiety or low mood
While MCAS is still an evolving area of research, some clinicians believe it may help explain why certain individuals with ADHD experience persistent physical symptoms alongside emotional and cognitive difficulties.
Understanding MCAS in ADHD could lead to new treatment options that target immune system regulation.
Dysautonomia and ADHD: When the Autonomic Nervous System Struggles
Dysautonomia refers to a group of disorders where the autonomic nervous system (ANS) does not work properly. The ANS controls involuntary functions like heart rate, blood pressure, digestion, and temperature regulation.
Many individuals with ADHD report symptoms consistent with dysautonomia, such as light headedness, rapid heartbeat, and digestive problems. These symptoms can interfere with concentration and emotional stability. Identifying dysautonomia in ADHD patients can help clinicians address these physical symptoms alongside traditional ADHD treatments.
Postural Orthostatic Tachycardia Syndrome (POTS) and Attention Difficulties
POTS is a form of dysautonomia characterised by an excessive increase in heart rate upon standing. Individuals with POTS may experience:
Dizziness or light-headedness on standing
Rapid heart rate
Fatigue and brain fog
Exercise intolerance
Studies show that POTS frequently co-occurs with ADHD, especially in young women. Early research suggests higher rates of ADHD-type attentional difficulties in individuals with POTS, raising important questions about shared mechanisms involving autonomic regulation and cognitive function.
The cognitive symptoms of POTS, such as difficulty focusing and mental fatigue, can mimic or worsen ADHD symptoms. Treating POTS through hydration, medication, and lifestyle changes may improve attention and overall functioning in affected individuals.
Gastrointestinal Difficulties Commonly Reported in ADHD
These may include:
Chronic abdominal pain
Bowel irregularity
Food sensitivities
Reflux or nausea
The gut-brain axis, a communication network between the digestive system and the brain, may play a role in this connection.
Gut inflammation or imbalances in gut bacteria can affect neurotransmitter production and brain function. Addressing gastrointestinal health through diet, probiotics, or medical treatment might reduce some ADHD symptoms, especially those related to mood and attention.
How These Physical Factors May Affect Attention, Emotion, and Daily Functioning
Physical health issues such as inflammation, joint pain, immune dysregulation, and autonomic dysfunction can create a cycle of discomfort and distraction. Pain or fatigue can reduce the brain’s capacity to focus. Mood swings linked to immune or autonomic problems can worsen emotional regulation.
For example, a child with ADHD and joint hypermobility might struggle with physical discomfort that distracts from schoolwork. An adult with ADHD and POTS may experience brain fog and fatigue that reduce work productivity. Recognizing these physical contributors allows for more comprehensive care.
What This Means for ADHD Assessment and Support
At CADS, we recognise that neurodevelopmental profiles do not exist in isolation. ADHD may intersect with physical health, sensory processing, emotional regulation, and nervous system functioning in complex ways.
While this emerging research does not mean that ADHD is caused by inflammation or physical illness, it does reinforce the importance of:
Taking a thorough developmental and medical history
Listening carefully to physical as well as cognitive experiences
Considering the impact of chronic health difficulties on attention, energy, and emotional regulation
Supporting individuals using a holistic, multidisciplinary framework
Understanding these brain–body connections may, over time, lead to more individualised and effective approaches to support.
Support plans might include physical therapy for joint issues, dietary changes for gut health, medications for inflammation or MCAS, and strategies to manage dysautonomia symptoms. This integrated approach can help individuals with ADHD achieve better outcomes.
A Note of Clinical Caution: What Research Can and Cannot Tell Us
While the links between ADHD and physical health factors are promising, research is still in early stages. Many studies have small sample sizes or rely on self-reported symptoms. Cause and effect relationships remain unclear.
These findings do not mean that all people with ADHD have these physical conditions or that treating them will cure ADHD. Instead, they highlight the need for more research and a broader view of ADHD that includes the whole person.
Final Thoughts: Towards a More Integrated Understanding of ADHD
ADHD is more than a brain disorder. It involves complex interactions between the brain, immune system, autonomic nervous system, and body tissues. Recognising these connections can improve how we assess and support people with ADHD.
By addressing physical health alongside cognitive and behavioural symptoms, clinicians and caregivers can help individuals with ADHD live fuller, more comfortable lives. This whole-body approach offers hope for more personalised and effective care.
Sources and Further Reading
This blog is informed by emerging research and is intended for educational purposes. It does not replace medical advice. Always consult an appropriately qualified healthcare professional regarding diagnosis or treatment. This blog draws on emerging research discussed in: Kustow, J. (2025). The Surprising Association Between ADHD & Inflammation. ADDitude Magazine.
The content has been adapted and summarised for a UK clinical and family audience by CADS Autism & ADHD.
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