Effects of Stress on the Immune System

Much has been written about the impact of stress on the immune response. However, what scientists have discovered about this is quite interesting. Humans and animals are endowed with a survival capability or mechanisms often called the “fight-or flight response”. This instinct serves the purpose of allowing the organism to sense danger and appropriately respond to it. The essence of this danger signal is a stress response, which forces the organism to make a choice to fight or attempt to flee. In this respect, the acute stressor was the stimulus for kicking the organism into action. Similarly, with the immune system, acute stress serves the purpose of forcing the immune system to respond to the stressor (whether the stressor is internal or an external pathogen like a virus or bacteria).

The acute immune response is designed to do what is necessary to quickly isolate and neutralize the cause of the acute stress and, in doing so, results in several enhancements in functionality that are necessary to resolve the situation. After the situation or stressor has been effectively neutralized, the immune system returns to its normal, steady state where vigilance is maintained but a heightened immune response is no longer needed.

The situation is quite different when the organism is under constant or chronic stress. When the stress response is constantly at a heightened level over a period of time, the immune response to stress is also at a heightened level in order to cope with the stressor and resolve the situation. Chronic stress means that hormones such as cortisol are always elevated. In the short-term, cortisol can improve the body’s immune response to stress and leads to other physiological benefits that are necessary in a fight-or-flight survival situation. Blood sugar levels are increased in order to divert resources to physiological functions that are needed to fight the stressor. Adrenaline, another stress hormone, is also released in response to give your body the energy it needs to fend off the attack. When the stressor is acute and short-term, the levels of these hormones return to normal and the body as well as the immune system returns to a steady state.

However, with long-term chronic stress, the body continually senses that it is in this fight-or-flight mode and doesn’t have the ability to return to baseline function, which is necessary for restoration and renewal. In this situation, over time, the stress response goes into a depleted state where the adrenal glands can no longer mount an effective reaction to the constant stressor, leading to adrenal exhaustion. The immune system follows with similar detrimental changes, which effectively decrease immune function over time. So, with acute stress, the immune response is enhanced but with chronic stress, the immune response is compromised, leading to dysfunction and disease.

How Does Stress Affect the Immune System?

Researchers have characterized several of the specific immune changes in acute versus chronic stress situations. Acute stress is defined as stressors lasting for minutes to several hours while chronic stress is defined as stress that lasts months to years. Acute stress can be an immune system booster. In acute stress, the immune system jumps into high gear and scientists have found that acute stress increases white blood cell mobilization and the innate immune response (the first line of defense, non-specific response that occurs immediately after the first sign of attack). It also leads to a more specific adaptive immune response (immune response that develops after several hours to days and is specific to the offending pathogen) and increased immune protection. By contrast, chronic stress leads to immune dysregulation where white blood cell mobilization is decreased, the effectiveness of the innate and adaptive immune responses is lessened, and there is an overall trend towards immune suppression.

Furthermore, the result of acute stress can be beneficial in practical effects by stimulating things like an increased efficacy of vaccines and improved wound healing. On the contrary, chronic stress can be harmful by decreasing the effectiveness of vaccines and reducing the ability to heal wounds resulting from injuries. It also leads to decreased resistance to infections and can cause chronic inflammation and autoimmune conditions.

Stress Impact on Mental and Physical Health

The fast-paced lives we live often manifest as dealing with one stressor after another. The challenges we face are certainly unique when compared to those faced by our ancestors and previous generations. Our always-on tendencies mean that we are always bombarded with chronic stress. Whether it’s responding to emails late at night, dealing with digital devices that are never shut off, always thinking about projects at work, worrying about our financial situations, or managing the needs of our kids, downtime is a thing of the past.

While productivity is always at a premium and we drive ourselves to constantly get ahead in life, there are real effects of stress on health and real ramifications of this behavior that society must deal with. Chronic stress and depleted immune function are contributors to the increased prevalence of chronic diseases. These include the effects of stress on mental health conditions such as anxiety and depression, as well as physical health issues like heart disease, sleep disruption, weight gain, and others. Dealing with the underlying stressors through lifestyle changes is paramount to overcoming these conditions as well as for ensuring our immune systems work like they are supposed to. It is important to employ strategies to address stress and health challenges.

Lifestyle changes like finding time to decompress and relax through meditation, breathing practices, massage, and other methods, ensuring we get regular exercise, creating and maintaining a healthy support network of friends and family, and volunteering to make a meaningful difference in the community are all techniques that are helpful for managing chronic stress.

Making sure we consume a healthy diet with plenty of water, fruits, vegetables, healthy fats, and adequate, clean sources of protein is also an essential practice for supporting immune function and dealing with stress. Smart supplementation with nutrients designed to enhance immunity and reduce the effects of stress on the body is also a good strategy. These are all good methods to employ to boost immune system health.

If you are doing all these things and making a real effort to deal with your stress from a lifestyle perspective, but not seeing the results you desire, it may be wise to seek professional help, whether through counseling or another practitioner that deals in managing stress. Overcoming the negative effects of our fast-paced lifestyles will pay real dividends in our ability to lead healthier, happy lives for years to come.