The Nervous System, Chronic Pain, and Headaches

Lisa Eisfeld
January 13, 2026

How the Sympathetic and Parasympathetic Systems Shape Your Pain Experience

If you live with chronic pain, headaches, migraines, or jaw tension, your nervous system may be playing a much bigger role than you realise. Pain is not only about muscles, joints, or posture; it is deeply influenced by how safe or threatened your nervous system feels.

Understanding the balance between the sympathetic and parasympathetic nervous systems can be a powerful step toward reducing pain and restoring ease in the body.

The Two Sides of the Autonomic Nervous System

Your autonomic nervous system runs automatically in the background, controlling breathing, heart rate, digestion, muscle tone, and stress responses. It has two main branches:

1. The Sympathetic Nervous System “Fight or Flight.”

This system is designed to keep you alive in moments of danger. Aka run away from the Tiger in the jungle. When active, it:

  • Increases heart rate and blood pressure
  • Tightens muscles (especially neck, shoulders, jaw)
  • Narrows blood vessels
  • Heightens alertness
  • Suppresses digestion and recovery

Short-term activation of the sympathetic nervous system is healthy and necessary. Chronic activation, however, is where problems begin.

2. The Parasympathetic Nervous System “Rest and Repair.”

This system supports healing, recovery, digestion, and calm. When active, it:

  • Slows heart rate and breathing
  • Relaxes muscles
  • Improves digestion and circulation
  • Reduces inflammation
  • Supports tissue repair and pain modulation

The parasympathetic state is where the body feels safe enough to heal.

Chronic Pain and a Stuck “Fight or Flight” State

Many people with chronic pain live in a constantly activated sympathetic state, even without obvious stress. This can happen due to:

  • Long-term emotional stress
  • Trauma or unresolved nervous system shock
  • Poor sleep
  • Chronic inflammation
  • Repetitive strain or poor posture
  • Persistent pain itself

Over time, the nervous system becomes sensitised, which means it overreacts to signals that are no longer dangerous. Pain becomes louder, longer, and harder to calm.

Headaches and Migraines: A Nervous System Perspective

Tension Headaches

Tension headaches are often linked to:

  • Chronic muscle contraction in the neck, shoulders, and scalp, and a restricted upper
  • cervical spine
  • Shallow breathing
  • Jaw clenching or teeth grinding

These are classic signs of sympathetic dominance.

Migraines

Migraines are not “just headaches”; they involve:

  • Nervous system hypersensitivity and central sensitisation
  • Heightened sensory processing
  • Reduced ability to down-regulate stress

Many migraine sufferers oscillate between overstimulation and exhaustion, showing a nervous system that struggles to find balance.

Jaw Pain, TMJ, and the Stress Response

The jaw is one of the first places stress shows up. Sympathetic activation can cause:

  • Jaw clenching or grinding (bruxism)
  • Tight tongue and facial muscles
  • Limited jaw opening
  • Referred pain to the head, neck, and ears

Because the jaw is closely connected to the vagus nerve and brainstem, chronic jaw tension can keep the nervous system stuck in a loop of stress and pain.

Why Pain Persists Even After “Healing”

Many people are told, “Your scans look normal, you should be fine.” But pain can continue when:

  • The nervous system still perceives the threat
  • Muscles remain guarded/ spasm
  • The brain expects pain based on past experiences

This does not mean pain is “all in your head.” It means pain is real, learned, and changeable.

Shifting from Sympathetic to Parasympathetic

Healing chronic pain often requires more than strengthening or stretching. It requires teaching the nervous system that it is safe again. Helpful approaches include:

  • Slow nasal breathing and extended exhales
  • Gentle neck, jaw, and tongue relaxation
  • Vagus nerve-supportive movements
  • Mindful body awareness (interoception)
  • Consistent sleep and rhythm
  • Reducing sensory overload

When the parasympathetic system comes online, pain signals often soften naturally.

A New Way to View Pain

Instead of asking, “What’s wrong with my body?”, try asking, “What does my nervous system need to feel safe?” This shift alone can change how pain is experienced.

How Specialised Head, Neck, and Jaw Physiotherapy Can Help

Specialised physiotherapy for the head, neck and jaw focuses not only on muscles and joints, but on how the nervous system is contributing to ongoing pain. A trained physio assesses upper cervical movement, jaw mechanics (TMJ), muscle tone, breathing patterns, and neural sensitivity. Gentle hands-on techniques to the upper neck and jaw, combined with targeted movement retraining, can reduce protective muscle guarding and improve joint and nerve function. Importantly, this approach helps calm an overactive nervous system, reducing sensitisation and restoring the brain’s sense of safety. Over time, pain becomes less reactive, movement feels easier, and headaches, migraines, and jaw symptoms often decrease in frequency and intensity.

In Conclusion

Chronic pain, headaches, migraines, and jaw pain are not just mechanical problems, they are nervous system experiences. When the body lives in survival mode for too long, pain becomes a protective response.

By gently supporting the parasympathetic nervous system, we create the internal conditions where healing is possible. Your body is not broken. It may simply be asking for safety, patience, and regulation.

The Headache Neck and Jaw Clinic offers expert treatment for chronic pain linked to the nervous system and head, neck and jaw conditions. Book an initial appointment today with one of specialist physiotherapists.