1.    Introduction
The autonomic nervous system, a crucial part of the peripheral nervous system, is responsible for supplying muscles and glands, thereby influencing the function of internal organs (1). A significant challenge facing the nervous system is the prevalence of autoimmune diseases. These chronic disorders result from a deficiency in immune tolerance to self-antigens. Contrary to common belief, autoimmune diseases are not rare, affecting approximately 5% of the global population (2). It appears that a complex interaction between genetic and environmental factors contributes to the onset of these conditions. In recent years, numerous studies have explored the phenomenon of multiple autoimmunities, which include the coexistence of two or more autoimmune diseases, as well as multiple autoimmune syndrome, characterized by the presence of three or more such diseases (3). Researchers have identified common underlying mechanisms that may explain the emergence of these multifaceted autoimmune responses in an individual. In addressing autoimmune diseases, both pharmacological treatments and non-pharmacological interventions are utilized. Among the strategies aimed at alleviating stress and mental tension in individuals with autoimmune conditions, meditation stands out as a prominent approach. This spiritual and healing practice has a history extending over five thousand years. According to the principles of yoga, meditation involves an interplay between heightened focus on a specific subject and deep introspection (4). It is a conscious mental process that, through regulated attention to chosen stimuli for a defined duration, can induce physiological changes in the body. In conclusion, understanding the intricate relationships between the autonomic nervous system, autoimmune diseases, and the therapeutic potential of practices like meditation is essential for advancing both treatment and quality of life for affected individuals.
2.    Methods
The present study was a library and systematic review, focusing on articles published in both Persian and English between January 2013 and mid-September 2024. The search for relevant literature was conducted across various databases, including Web of Science (WOS), the Scientific Information Database (SID), Magiran, Scopus, PubMed, ISC, and Google Scholar. The key search terms were: 'Meditation,' 'Breathing exercises,' and 'Cold exposure.' Our objective was to examine only those articles that utilized the Wim Hof Method. From an initial pool of 400 identified articles, five met our inclusion criteria. These criteria specified that the articles must investigate various applications of breathing exercises, meditation, and cold exposure within the framework of the Wim Hof Method. Additionally, selected studies had to ensure that participants underwent medical examinations before engaging in the exercises. Conversely, articles were excluded if they did not employ the Wim Hof Method to assess its impact on the autonomic nervous system or if participants had not undergone medical testing. Since our focus was strictly on individuals using the Wim Hof Method, alternative methods for disease control or treatment were disregarded. Ultimately, five articles discussing the effects of meditation, breathing exercises, and cold exposure through the Wim Hof Method on the autonomic nervous system were critically analyzed. To assess the quality of the selected articles, the Downs and Black questionnaire was employed, providing a structured framework for evaluating the methodological rigor of the studies.
3.    Results
The present study analyzed five articles obtained through a systematic search based on specific inclusion criteria. All five articles focused on the effects of the Wim Hof Method—which involves meditation, deep breathing, and cold exposure—on the autonomic nervous system. One article indicated that practices associated with the Wim Hof Method significantly reduced perceived stress levels. Additionally, a review of two articles demonstrated that young individuals who employed the Wim Hof Method were able to withstand injections of bacterial endotoxins—known to cause body tremors and headaches—without exhibiting symptoms, whereas a control group not using this method experienced these symptoms. Furthermore, an examination of two additional articles revealed that the application of the Wim Hof Method could improve conditions related to autoimmune diseases through its effects on the autonomic nervous system. The findings showed an overall average quality assessment of the articles at 57.82%. Notably, the lowest quality score was 70.96%, while the highest quality score, recorded for two articles, was 90.32% (Table 1).

Table 1. Evaluation of the quality of the reviewed articles by Downs and Black questionnaire.

4.    Conclusion
The present study provides an overview of research on the effects of various forms of meditation, breathing exercises, and cold exposure on the nervous system to improve or manage autoimmune diseases. Autoimmune diseases have significantly increased in prevalence within modern societies. Many of these conditions require the use of pharmaceutical medications, which, while potentially effective in treating or controlling the disease, may also lead to adverse side effects. The use of herbal remedies, along with practices such as meditation and physical exercise, can prove beneficial in managing or treating certain autoimmune diseases, often with fewer side effects. However, further research is needed in this area. A prevalent issue in society is stress, which disrupts individuals' daily lives and activities. Stress can arise from various factors, one of which is perceived stress. Perceived stress refers to an individual's response to a stressful event, which is not solely determined by the event's intensity or inherent qualities (19). Researchers have emphasized the importance of considering not just objective stress, but also its cognitive evaluation, which plays a critical role in triggering psychological stress. Cognitive evaluation involves assessing the resources available to address the situation. When these resources are perceived as insufficient, perceived stress emerges (20, 21). Autoimmune diseases are another significant health concern. While the innate immune system is vital for survival, persistent inflammatory cytokine production can damage organs and tissues. Autoimmune diseases occur when the immune system fails to differentiate between self-cells and foreign invaders, leading to attacks on the body's tissues and organs. Conditions such as rheumatoid arthritis and inflammatory bowel disease are examples of autoimmune diseases. While medications that suppress inflammatory cytokines or their receptors have proven effective, they are often expensive and accompanied by serious side effects (22, 23). Practicing meditation, breathing exercises, and cold exposure in the Wim Hof Method appears to affect the body's autonomic nervous system and may help improve or control autoimmune diseases.
Ethical Considerations
Compliance with ethical guidelines
There were no ethical considerations to be addressed in this research.
Funding
This research did not receive any financial support from government, private, or non-profit organizations.
Authors' contributions
All authors contributed equally to preparing the article.
Conflicts of interest
The authors declare that there are no conflicts of interest associated with this article.