Why Nervous-System States Shift

Week 6 of the Nervous-System States (Modes) Series

Why the same nervous system can feel completely different from one moment to the next.

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Recognizing the Experience

Many people notice that their symptoms do not remain the same from one day to the next—or even from one hour to the next.

A person may move from hyperarousal into shutdown, from shutdown into motor activation, or from feeling emotionally connected to feeling detached or unreal.

Some people notice different states at different times of day. Others find that poor sleep, stress, illness, overstimulation, or physical exertion seem to make the nervous system shift more easily between recognizable patterns.

These changes often feel sudden and unpredictable. People frequently describe feeling discouraged because symptoms seem to disappear, return, or change form rather than steadily improve.

Although these shifts may feel random, many people eventually begin recognizing recurring patterns.

What Is Happening?

The nervous system continuously integrates information from within the body and the external environment as it monitors and regulates the body's overall physiologic condition.

As the overall physiologic state changes, different nervous-system modes may emerge.

The nervous system continuously adjusts patterns of activation, engagement, movement, body awareness, and perception in response to changing internal and external conditions.

During withdrawal, these patterns may become less stable and more reactive. As a result, the nervous system may shift more readily from one mode to another.

These shifts do not necessarily mean that a new illness has developed. In many cases, they reflect the same nervous system reorganizing into a different overall state.

What Is Changing in the Body?

Different nervous-system states reflect different patterns of activity across multiple interacting brain–body systems.

As the body's overall physiologic state changes, activation, autonomic regulation, movement, body awareness, emotional engagement, and perception may all change together.

Rather than changing one symptom at a time, the nervous system reorganizes into different overall patterns of function.

These shifting patterns influence how the body feels, how the surrounding world is experienced, and which symptoms become most noticeable at a given moment.

Connection to the Five-Axis Stress Biology Framework™

Within the Five-Axis Stress Biology Framework™, shifting nervous-system modes reflect changing patterns of signaling across brain and body.

Changes in stress regulation (Axis 1), amplification and excitability processes (Axis 2), autonomic regulation (Axis 3), movement and motor regulation (Axis 4), and neuroimmune/visceral activation (Axis 5) may all contribute to these changing patterns over time.

A shift between nervous-system modes does not usually reflect one system turning on while another turns off. Instead, it reflects changing patterns across these multiple interacting brain–body systems.

Why These Changes Can Feel So Confusing?

State shifts often feel frightening because the overall experience of symptoms may change dramatically.

A person may wake feeling intensely activated, later become emotionally flat, and by evening experience inner restlessness or altered perception.

These changes can create the impression that several different illnesses are developing at the same time. In reality, the same nervous system may simply be moving through different physiologic states.

The experience is real because the underlying nervous system states are real.

Important Clarification

Shifting between nervous-system states does not necessarily mean permanent worsening or new damage has occurred.

Many people move repeatedly between different modes throughout withdrawal, especially during periods of poor sleep, physiologic strain, illness, or overstimulation.

These changes reflect shifting patterns of nervous-system regulation rather than personal weakness, failure, or a new disease.

Figure 6. Nervous-system states can shift, overlap, and transition over time as patterns across interacting brain–body systems change.

Looking Ahead

Nervous-system states do not always remain separate or clearly defined.

Many people experience features of more than one state simultaneously.

In the next article, we will examine mixed nervous-system states and why seemingly opposite experiences can occur together.

Selected Scientific References

1. McEwen, B. S. (1998). Protective and damaging effects of stress mediators. New England Journal of Medicine, 338(3), 171–179.

2. Thayer, J. F., & Lane, R. D. (2000). A model of neurovisceral integration in emotion regulation and dysregulation. Journal of Affective Disorders, 61(3), 201–216.

3. Livneh, Y., Sugden, A. U., Madara, J. C., et al. (2020). Estimation of Current and Future Physiological States in Insular Cortex. Neuron, 105(6), 1094–1111.

4. Menon, V., & Uddin, L. Q. (2010). Saliency, switching, attention and control: A network model of insula function. Brain Structure and Function, 214(5), 655–667.