The Relationship Between Chronic Stress and the Immune System

Written by Kimiya Mansour | Edited by Mehr Bawa

Photo by Andrew Neel

For some people, stress has played a contributing factor in their everyday life; in fact, the American Psychological Association (APA) states that 27% of Americans reported experiencing intense stress to the point of not being able to comply with their daily routine [1]. The words “stress” and “anxiety” have the tendency to be overused in society, further removing them from their intended definitions. For the clarity of this article it is paramount to adhere to the definition of these words based on the National Institute of Health (NIH). According to the NIH, stress is caused by an external factor, such as a student taking a final exam, and can be eliminated once the external factor has been completed. Conversely, anxiety has an internal cause, meaning it is a direct response of how an individual reacts to chronic, constant, stress, and has a negative influence in one’s routine [2]. Although clinically distinguishable, stress and anxiety can intertwine and cause an individual to suffer from insomnia, high blood pressure, and constant headaches or body pain [2]. The objective of this article is to describe the harmful effects of chronic stress, the psychological and physiological response to a continuous stressor, on the immune system [3, 4]. 

Chronic stress can inhibit proper immune system function by decreasing immune cell counts and/or increasing active immunosuppressive mechanisms, both of which lower the body’s overall immune response[5]. Specifically, a stressed individual will have high levels of a hormone called cortisol, which lowers the number of lymphocytes, which are white blood cells that make antibodies to protect the body against infections [6]. As a result, individuals with chronic stress are more susceptible to infections because their defense mechanisms have been reduced. In terms of active immunosuppression, chronic stress increases one’s regulatory T cells (Tregs), which are a type of white blood cell. When one is not overly stressed, Tregs attack foreign pathogens, but Tregs hyper-activated by chronic stress overstimulate and weaken the immune system, which can lead to autoimmune disease [7,8]. 

Although most forms of stress are detrimental, short-term stress (lasting several minutes to hours) can be beneficial [9]. For instance, short-term stress can help one prepare for challenges and activate the fight-or-flight response, which is when the nervous system raises one’s blood pressure and heart rate to be able to take action in a stressful situation [9, 10].

All in all, it is important to manage one’s chronic stress, instead of accepting it as a constant factor in one’s life. The NIH recommends individuals to recognize their triggers and work on coping techniques that best work for them [2]. For example, one can keep a journal and write down their thoughts and feelings, download a relaxation app that encompasses relaxation exercises, participate in an active exercise, maintain a healthy sleep routine, avoid having an excessive caffeine intake, and reach out to friends and family for support [2]. Despite the fact that chronic stress cannot be alleviated overnight, each person can gradually select an option that will work for them and gradually manage their chronic stress.

References:

1. Bethune, Sophie. “More than a quarter of U.S. adults say they’re so stressed they can’t function.” American Psychological Association, 19 October 2022, https://www.apa.org/news/press/releases/2022/10/multiple-stressors-no-function. Accessed 23 October 22.
2. “I’m So Stressed out! Fact Sheet.”NIH. gov, https://www.nimh.nih.gov/health/publications/so-stressed-out-fact-sheet. Accessed 18 October 2022.
3. “Chronic Stress.” Yale Medicine. https://www.yalemedicine.org/conditions/stress-disorder#:~:text=%E2%80%A2A%20consistent%20sense%20of,changes%2C%20medications%2C%20setting%20realistic%20goals. Accessed 22 October 2022. 
4. “APA Dictionary of Psychology.” American Psychological Association. https://dictionary.apa.org/chronic-stress. Accessed 11 November 2022.
5. Dhabhar F. S. (2009). Enhancing versus suppressive effects of stress on immune function: implications for immunoprotection and immunopathology. Neuroimmunomodulation, 16: 300–317. 
6. Dhabhar, F. S., McEwen, B. S. (1997). Acute stress enhances while chronic stress suppresses cell-mediated immunity in vivo: a potential role for leukocyte trafficking. Brain, behavior, and immunity, 11: 286–306. 
7. Kondĕlková, K., Vokurková, D., Krejsek, J., Borská, L., Fiala, Z., Ctirad, A. (2010). Regulatory T cells (TREG) and their roles in immune system with respect to immunopathological disorders. Acta medica (Hradec Kralove), 53: 73–77. 
8. Vignali, D. A., Collison, L. W., Workman, C. J. (2008). How regulatory T cells work. Nature reviews. Immunology, 8: 523–532. 
9. Dhabhar F. S. (2014). Effects of stress on immune function: the good, the bad, and the beautiful. Immunologic research, 58: 93–210. 
10. “What Happens to Your Body During the Fight or Flight Response?” Cleveland Clinic. 9 December 2019. https://health.clevelandclinic.org/what-happens-to-your-body-during -the-fight-or-flight-response/. Accessed 11 November 2022.