If you’re autistic and/or ADHD and you’ve spent years collecting diagnoses that don’t seem connected – gut issues, dizziness, chronic pain, fatigue, inflammation – you’re not imagining patterns that aren’t there.
For a long time, neurodivergence was framed almost entirely as a “brain thing”. Yet the nervous system isn’t just the brain. It includes the autonomic nervous system that regulates digestion, heart rate, blood pressure, pain processing and energy. Increasingly, research is showing that many neurodivergent people experience differences across this whole system, not just in cognition or behaviour.
This doesn’t mean autism or ADHD directly cause medical conditions. But the body and brain are constantly talking to one another – and sometimes that conversation shows up physically.
Why people talk about a “dysregulated nervous system”
When clinicians and researchers talk about nervous system regulation, they are usually referring to how flexible and responsive the autonomic nervous system is. Some neurodivergent individuals experience differences in interoception, sensory processing and stress physiology which, over time, can influence digestion, sleep, pain thresholds, temperature regulation and fatigue levels. Rather than being purely psychological, these symptoms reflect the nervous system’s role as a whole-body network.
What research is beginning to show
Several areas are being explored in the literature:
- Gut health: autistic people report higher rates of gastrointestinal symptoms such as constipation, abdominal pain and IBS-type patterns. Research into the gut-brain axis is ongoing.
- Autonomic function: some studies suggest higher rates of orthostatic intolerance and dysautonomia symptoms, including POTS-like presentations, particularly where hypermobility is also present.
- Pain and fatigue: overlaps between neurodivergence, central sensitisation, fibromyalgia-type pain and chronic fatigue patterns are being explored in emerging research.
Importantly, these are associations, not simple cause-and-effect explanations. The story is complex and still evolving.
Why so many people feel dismissed
Many neurodivergent adults describe being told symptoms are “just anxiety” when their experiences don’t fit neatly into one specialty. When symptoms cross multiple systems – gut, nervous system, cardiovascular, immune – they can be harder to categorise. Anxiety can absolutely affect the body. But physical symptoms can also exist alongside anxiety. One doesn’t erase the other.
What might help if this resonates
If you recognise yourself in this conversation, gentle self-advocacy can make a real difference:
- Track patterns over time – sleep, sensory load, hormonal shifts, hydration, movement and stress can all influence symptoms
- Bring concise notes into appointments. Clinicians often respond better to patterns than isolated events
- Ask collaborative questions such as “What possibilities are we ruling out?” or “Would an autonomic assessment be relevant here?”
- Seek a second opinion if symptoms remain unexplained or you don’t feel heard. A fresh perspective is part of good healthcare, not a failure
- Remember that believing your own lived experience isn’t being difficult – it’s being informed
You deserve clinicians who look at the whole system, not just one symptom at a time. And you deserve to feel safe, respected and taken seriously when you talk about your body.
Lived experience matters too
Many people with ME/CFS, hypermobility or chronic pain describe discovering their neurodivergence later in life and finally understanding their nervous system through a wider lens. Personal stories from organisations such as Action for ME, The ME Association and The Ehlers-Danlos Society highlight how complex and overlapping these journeys can be.
References
Leader et al (2022) Systematic review of gastrointestinal symptoms in autism – PMC9003052
Wang et al (2022) Meta-analysis on gastrointestinal symptoms in ASD – Frontiers in Psychiatry
Ng et al (2025) ADHD and IBS association meta-analysis – PubMed 40456878
Owens et al (2021) Autonomic dysfunction in autism – PMC8756818
Csecs et al (2022) Neurodivergence, hypermobility and dysautonomia symptoms – PMC8847158
Grant et al (2022) Autism and central sensitisation symptoms – PMC8842858
Leaver et al (2024) ADHD and fibromyalgia review – PMC11046556
Sáez-Francàs et al (2012) ADHD in chronic fatigue syndrome cohort – Psychiatry Research
Photo by Ahmet Sali on Unsplash