How thoughts and emotions affect the body: Hypnotherapy and physiological effects

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Author: Camilla E.
Certified Hypnotherapist
Founder, CE-Hypnosis, Sweden
The author’s surname is omitted for personal security reasons.  Camilla is a certified hypnotherapist, not a healthcare professional.

Last updated: 11 feb, 2025​​​​​​​​​

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This article is intended for informational purposes

and is based on scientific evidence as well as practical

observations from certified hypnotherapy practice.

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Hypnotherapy may influence the immune system and allergic symptoms through interactions between the nervous system, stress, and immune function. Research in psychoneuroimmunology demonstrates how thoughts, emotions, and stress can modulate inflammation and symptom severity.

Concurrently, certified hypnotherapists report clinical observations in which allergic symptoms—such as pollen and pet allergies—decreased following therapy sessions.

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This article summarizes both scientific studies on hypnosis, the distinction between hypnosis and hypnotherapy, and practical clinical observations that warrant further investigation.

 

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Abstract

 

Extensive research in psychoneuroimmunology indicates that psychological factors such as stress, emotions, and cognitive processes can influence immunological and inflammatory mechanisms through well-defined neuroendocrine and autonomic pathways. Studies suggest that hypnotherapy has the potential to modulate autonomic function, perception, and symptom severity in various somatic conditions, including allergic rhinitis.

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In clinical practice as a certified hypnotherapist, observations indicate recurring instances in which clients report reduced or practically resolved allergic symptoms after hypnotherapy. These observations lack systematic scientific documentation and should be regarded as hypothesis-generating.

This article summarizes the current research, describes practical observations, and discusses scientific criticisms as well as the need for future studies.

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Psychological influences on allergic symptoms

Neuro-immunological mechanisms underlying allergic symptoms and hypnotherapy

 

Psychoneuroimmunology (PNI) examines the interactions among the central nervous system (CNS), autonomic nervous system (ANS), endocrine system, and immune function. Psychological processes can influence physiological mechanisms via these integrated systems.

Stress activates the hypothalamic-pituitary-adrenal (HPA) axis, leading to the release of cortisol and catecholamines, which affect immune cell function and inflammatory processes. Chronic stress has been associated with increased inflammation, altered immune balance, and exacerbated somatic symptoms.

The autonomic nervous system regulates inflammation directly via the cholinergic anti-inflammatory reflex, in which the vagus nerve suppresses pro-inflammatory cytokines. Prolonged sympathetic dominance, often observed during chronic stress, is associated with:

• Elevated levels of systemic inflammation

• Altered immune balance

• Exacerbated somatic symptoms

Immune responses can also be classically conditioned, illustrating that the CNS can modulate peripheral immune reactions.

 

 

Part I – Scientific background

Stress and the HPA axis

Psychoneuroimmunology demonstrates the bidirectional communication between the brain and the immune system. Psychological processes influence physiological mechanisms through integrated neuroendocrine and autonomic pathways.

Stress activates the hypothalamic-pituitary-adrenal (HPA) axis, leading to cortisol and catecholamine release. These hormones modulate immune cell activity, cytokine expression, and inflammatory processes. Chronic stress correlates with systemic inflammation, dysregulated immune responses, and impaired disease resistance.

 

Autonomic regulation of inflammation

The autonomic nervous system plays a direct role in immune modulation. The cholinergic anti-inflammatory pathway via the vagus nerve can suppress inflammatory cytokine production and regulate immune responses.

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Chronic sympathetic dominance, often seen in prolonged stress, is associated with:

• Increased systemic inflammation

• Altered immune homeostasis

• Exacerbated somatic symptoms

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Conditioning of immune responses

Experimental evidence shows that immune responses can be classically conditioned. Immunosuppressive or allergic responses can be elicited by psychological stimuli following conditioning, demonstrating CNS influence on peripheral immunity.

 

Hypnotherapy and brain activity

 

Neurophysiological effects

 

Neuroimaging studies reveal that hypnosis modulates brain activity in regions involved in attentional control, perception, and autonomic regulation, including the anterior cingulate cortex, insula, and prefrontal cortex.

 

Clinically, hypnosis has documented effects on:

• Pain modulation

• Autonomic nervous system activity

• Symptom perception

• Stress regulation

 

Distinction between Hypnosis and Hypnotherapy

It is critical to distinguish between general hypnosis and clinical hypnotherapy:

• Hypnosis: A state of focused attention and increased suggestibility, often used in experimental or demonstration contexts.

• Hypnotherapy: A structured, goal-oriented therapeutic method employed by certified practitioners, utilizing systematic interventions, individualized approaches, and techniques for symptom and stress management.

This distinction differentiates hypnotherapy from demonstration or “stage hypnosis” and increases the reproducibility of effects on physiological and psychological processes, including stress and symptom modulation.

Research on allergic conditions has largely focused on hypnosis rather than structured hypnotherapy, implying that documented effects in studies may not fully reflect outcomes achievable through individualized therapeutic hypnotherapy—a critical research consideration.

 

Evidence in allergic conditions

A limited number of controlled studies have investigated hypnosis in allergic rhinitis. These studies report significant symptom reduction, improved quality of life, and decreased medication use. However, they do not show changes in IgE sensitization, indicating effects are primarily symptomatic.

It is important to note that most research focuses on general hypnosis rather than structured hypnotherapy. The distinction is crucial: study protocols typically involve standardized, short sessions, whereas hypnotherapy is structured, goal-oriented, individualized, and conducted by certified practitioners.

In other words, current evidence describes the effects of hypnosis on allergic symptoms, but the potential difference between hypnosis and therapeutic hypnotherapy remains unstudied and represents a relevant research question.

 

 

Part II – Observations from Hypnotherapy

 

Autonomic modulation

 

In hypnotherapy practice, recurring reports describe clients experiencing marked reduction or practical cessation of allergic symptoms after therapy.

 

Observed cases include:

• Pollen allergy

• Pet allergy

• Sensitivity to odors

 

Clients report that after the recommended number of hypnotherapy sessions (3–6 sessions of 2 hours each), they can be exposed to previous allergens without typical symptoms such as sneezing, watery eyes, itching, or respiratory discomfort. Reduced or ceased reliance on allergy medications has also been noted.

 

These outcomes are based on real-world client reports and therapeutic follow-up. They are hypothesis-generating and should not be interpreted as evidence of immunological cure, though they are biologically plausible and justify further systematic investigation.

 

Scientific interpretation

 

Several biologically plausible mechanisms may explain these observations:

• Modulation of autonomic regulation of inflammatory responses

• Reduced stress-induced cytokine activity

• Reconditioning of immune responses

• Central modulation of symptom perception

 

Currently, no evidence supports the elimination of underlying IgE-mediated sensitization. These observations should be regarded as hypothesis-generating clinical data rather than evidence of immunological cure.

 

 

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Part III – Scientific criticisms

 

Allergy is a strictly immunological disease:

Allergic sensitization is immunological, yet symptom intensity and inflammatory responses are known to be influenced by CNS-mediated neuro-immunological pathways.

 

Effects are purely placebo:

Placebo effects involve measurable neurobiological processes, including changes in brain activity and immune regulation. Hypnosis can be viewed as a structured method to enhance top-down regulation rather than an unspecific placebo effect.

 

Studies demonstrate physiological changes beyond placebo, including reduced pain, improved gastrointestinal function, and symptom reduction in allergy (Palsson et al., 2002; Langewitz et al., 2005; Schaefert et al., 2014).

 

Results are purely subjective

Randomized trials and systematic reviews report objective improvements in quality of life, symptoms, and physiological markers (Whitehead, 2006; Tan, Hammond, & Joseph, 2005).

 

No clinical studies on hypnotherapy

Correct: most controlled studies focus on hypnosis. Practical observations from certified hypnotherapists, however, suggest promising outcomes, warranting systematic research (Carlson et al., 2018; NCCIH, n.d.).

 

Observations lack scientific value

Systematic clinical observations can serve as hypothesis-generating data and motivate controlled trials, particularly when biologically plausible.

 

 

Part IV – Scientific rationale for further research

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Biological plausibility:

Strong evidence exists for neuro-immunological connections, including stress-induced effects on inflammation and autonomic immune regulation.

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Consistency with established clinical practice:

Psychological interventions are evidence-based for various somatic conditions (e.g., IBS, chronic pain, functional neurological symptoms) where central mechanisms influence peripheral processes.

 

Clinical signals:

Repeated reports of practically resolved allergic symptoms represent a potentially important research signal warranting systematic evaluation.

 

Low risk profile:

Hypnotherapy is a non-invasive, low-risk intervention and may complement medical treatment.

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Part V – Research Needs and Initiatives

Future studies should:

• Employ randomized controlled designs

• Include objective biomarkers (IgE, cytokines)

• Apply standardized and individualized interventions

• Incorporate long-term follow-up

 

A critical research question concerns the difference between general hypnosis (dominating current literature) and structured hypnotherapy. This distinction is largely absent in published studies, meaning current evidence may not reflect the effects achievable through structured, therapeutically oriented hypnotherapy by certified practitioners.

 

CE-Hypnosis is willing to participate in future studies systematically investigating these observations and comparing the effects of hypnosis versus therapeutic interventions.

 

 

Conclusion

 

here is strong scientific evidence that psychological processes can influence immunological and inflammatory mechanisms via neuro-immunological pathways. Hypnotherapy can modulate these systems and has demonstrated symptom effects in allergic conditions in limited studies.

 

Observations from hypnotherapists regarding practically resolved allergic symptoms represent a biologically plausible and relevant phenomenon that lacks systematic scientific evaluation.

 

A central research question is distinguishing hypnosis from hypnotherapy: current studies focus almost exclusively on hypnosis, while the potential effects of structured, therapeutically targeted hypnotherapy remain scientifically untested. This constitutes a clear hypothesis motivating further research.

 

 

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References

 

Bircher, A. (1999). Effect of self-hypnosis in patients with pollinosis. Swiss Medical Weekly, 129(1–2), 35–39. https://pubmed.ncbi.nlm.nih.gov/10077719/
Comment: Demonstrates that self-hypnosis can reduce symptoms of allergic rhinitis, supporting the section on practical effects on allergies.

 

Khansari, D. N., Murgo, A. J., & Faith, R. E. (1990). Effects of stress on the immune system. Immunology Today, 11(5), 170–175. https://doi.org/10.1016/0167-5699(90)90069-L

Comment: Provides evidence on how stress affects the immune system and the connection between psychology and physiology.

 

Kiecolt-Glaser, J. K., McGuire, L., Robles, T. F., & Glaser, R. (2002). Emotions, morbidity, and mortality: New perspectives from psychoneuroimmunology. Annual Review of Psychology, 53, 83–107. https://pubmed.ncbi.nlm.nih.gov/11752480/
Comment: Supports the link between emotions, stress, and physical disease processes.

 

Langewitz, W., Izakovic, J., Wyler, J., Schindler, C., Kiss, A., & Bircher, A. J. (2005). Effect of self-hypnosis on hay fever symptoms – A randomized controlled intervention study. Psychotherapy and Psychosomatics, 74(3), 165–171. https://doi.org/10.1159/000084001
Comment: RCT showing reduced symptoms of pollen allergy after hypnosis; reinforces the section on practical allergy observations.

 

Madrid, A., Rostel, G., Pennington, D., & Murphy, D. (1995). Subjective assessment of allergy relief following group hypnosis and self-hypnosis: A preliminary study. International Journal of Clinical and Experimental Hypnosis, 43(4), 308–317. https://pubmed.ncbi.nlm.nih.gov/8871357/
Comment: Preliminary study showing subjective symptom reduction with hypnosis; used to motivate further research.

 

National Center for Complementary and Integrative Health. (n.d.). Hypnosis. https://nccih.nih.gov/health/hypnosis
Comment: Summary from a U.S. authority supporting evidence for hypnosis in IBS, pain, and anxiety.

 

Palsson, O. S. (2015). Hypnosis treatment of gastrointestinal disorders: A comprehensive review of the empirical evidence. American Journal of Clinical Hypnosis, 58(2), 134–158. https://pubmed.ncbi.nlm.nih.gov/26264539/
Comment: Comprehensive review of hypnosis for gastrointestinal disorders.

 

Palsson, O. S., Turner, M. J., Johnson, D. A., Burnett, C. K., & Whitehead, W. E. (2002). Hypnosis treatment for severe irritable bowel syndrome: Investigation of mechanism and effects on symptoms. Digestive Diseases and Sciences, 47(11), 2605–2614. https://pubmed.ncbi.nlm.nih.gov/12452403/
Comment: RCT on IBS showing symptom reduction; cited in the section on gut-directed hypnotherapy.

 

Schedlowski, M., & Schmidt, R. E. (1996). Stress and the immune system. Naturwissenschaften, 83(3), 79–87. https://pubmed.ncbi.nlm.nih.gov/8668232/
Comment: Provides mechanistic evidence of how stress affects the immune system, linking psychology and physiology.

 

Schaefert, R., Klose, P., Moser, G., & Hauser, W. (2014). Efficacy, tolerability, and safety of hypnosis in adult irritable bowel syndrome: Systematic review and meta-analysis. Psychosomatic Medicine, 76(5), 389–398. https://www.ncbi.nlm.nih.gov/books/NBK242573/
Comment: Meta-analysis showing hypnosis is safe and effective in IBS; used to support evidence-based claims.

 

Tan, G., Hammond, D. C., & Joseph, G. (2005). Hypnosis and irritable bowel syndrome: A review of efficacy and mechanism of action. American Journal of Clinical Hypnosis, 47(3), 161–178. https://pubmed.ncbi.nlm.nih.gov/15754863/
Comment: Review of hypnosis for IBS with mechanistic discussion on physiological effects.

 

Thornton, L. M., Andersen, B. L., & Carson, W. E. (2006). Psychoneuroimmunology examined: The role of subjective stress in immune change. Brain, Behavior, and Immunity, 20(4), 378–386. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2473865/
Comment: Supports the link between subjective stress, hypnosis, and immune responses.

 

Whitehead, W. E. (2006). Hypnosis for irritable bowel syndrome: The empirical evidence of therapeutic effects.International Journal of Clinical and Experimental Hypnosis, 54(1), 7–20. https://pubmed.ncbi.nlm.nih.gov/16316880/
Comment: Summarizes empirical evidence for hypnosis in IBS, supporting both symptom and mechanistic sections.