Something that has become a universal truth and an unquestionable argument is that stress affects the immune system. This is due to the simple fact that at some point we have become ill, even with a cold, when we were in a stressful situation or context.
Thus, everyone knows that being subjected to high levels of stress results in a deficit in the function of our immune system, but we know little about why and how the immune system and stress are related.
Immune system weakened by stress
The immune system has the function of protecting us from organisms that cause disease. Immune system cells are found in the blood in the form of white blood cells (lymphocytes) and are also found in various organs, including the bone marrow, thymus, lymph nodes, and spleen.
Lymphocytes are responsible for creating antibodies. When antibodies detect a threat, they bind to lymphocytes to destroy the malignant agents.
So how is the immune system affected by stress? At the psychological level, stress activates the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system. This results in the production of two hormones: cortisol and epinephrine. Acute increases in cortisol and epinephrine are related to a decrease in the number of white blood cells in circulation.
The body begins to normalize the elevated level of stress by producing high levels of stress hormones even after the stressful event. This poses a prolonged threat to the immune system, making it increasingly difficult to recover. Short-term suppression of the immune system is not dangerous. However, chronic stress leaves the body vulnerable to infections and diseases.
Stress responses also have an effect on the digestive system. During a stressful event digestion is inhibited and after the episode digestive activity increases. This can affect the health of the digestive system and cause ulcers. The adrenaline released during a stress response is also another factor causing ulcers. Stress can also affect the immune system by raising blood pressure. Hypertension (consistently elevated blood pressure over several weeks) is a major risk factor in coronary heart disease (CHD).
The most common signs of a weakened immune system are swollen lymph nodes, recurrent colds and cold sores, and chronic illnesses. In the long term, cardiovascular problems, asthma, diabetes, or cancer can develop.
Stress factors and their relationship with the immune system
The first studies on stress and the immune system date back to the 1980s, when psychologist Janice Kiecolt-Glaser and immunologist Ronald Glaser studied the phenomenon for 10 years.
To do this, they observed their students for ten years. In this study, for example, they discovered that during exam periods, students almost stopped producing gamma interferon, which stimulates immunity, and T cells that fight infections.
From this point on, there was extensive research that took into account periods of stress, the age of those affected and underlying conditions of the study participants. Stress triggers such as exams, bereavement, divorce, unemployment, or caring for a family member with Alzheimer’s disease were also taken into account. In this way, stress and its causes are related to the response at a physical level.
In addition to the physical response that a high level of stress generates, we cannot forget that people with stress sleep less and exercise less, eat poorly, and in some cases smoke more or consume alcohol and other drugs. Obviously, these habits also affect the immune system.
It is first worth clarifying that a stressor can be defined as an event that exceeds an individual’s perceived ability to cope with it. This means that what may seem like an unimportant thing to some, may be perceived as a threat to others. The intensity, severity, controllability, and predictability of the stressor also play a major role in stimulating the brain and secreting stress hormones. Physiological reactivity to stressors is commonly observed even after repeated exposure to the same stressor.
With this in mind we understand that not everyone will have the same physiological response or level of stress, so there is no “one size fits all” solution. Stress treatment should address it from a psychosocial, physical, nutritional and pharmacological perspective. To adequately manage stress in both healthy and ill individuals, multidisciplinary approaches including psychopharmacological treatment, education, cognitive behavioural therapy, mindfulness-based approaches and relaxation techniques should be provided at an early stage, particularly in physically ill patients.
In everyday life, this can be developed through meditation, yoga, therapy and aerobic physical exercise. It is also important to observe the mechanisms developed by each patient, since a person who deals with stress through smoking is not the same as someone who develops sleep problems.
Walking alone, singing or listening to music, and maintaining communication and ties with people close to you have been shown to reduce cortisol levels and quiet thoughts related to the stressful event.
The complexity of stress, the relationship between the brain and our immune system, as well as its causes and related events, mean that the strategy to combat it must be multidisciplinary and adapted to the person affected.
