How Does Stress Impact the Immune System?

Sad and depressed woman sitting on sofa at home.

Maria Korneeva/Moment/Getty

Stress is a natural response of our bodies. It's a physiological response to our environment when we receive the message that there may be a threat. While it's an important function, it can get out of control, and it can affect our lives in negative ways.

You likely know that long term stress isn't healthy, and you may be aware that it affects your immune system, but you probably aren't familiar with the details of why stress is a problem for it. Ahead, we'll discuss why stress is important to manage for the sake of your nervous system, how it affects your body's ability to fight inflammation, infection, and disease, and what you can do to lower your stress levels.

First, let's make sure we understand the different types of stress, and why one is a problem while the other isn't.

Acute vs Chronic Stress

There are many different types of stress, but for simplicity's sake we are going to discuss the differences between the two types we deal with the most.

Acute Stress

As the name implies, acute stress is stress that occurs on a short term basis. It's the term for in the moment occurrences that our bodies responds to with a "stress response," which is the physiological reaction to feeling threatened where your body pumps out stress hormone cortisol, as well as other hormones meant to help you survive. You may feel like your heart is beating loudly, or fast; your breathing can become shallow; and your blood pressure can increase.

Acute stress is typically experienced as a fight or flight response. Chances are, you know this feeling well. Blood is sent to our muscles, so that if we need to engage in a physical fight, our chances of winning are improved, and if we need to run from a threat, we can go faster.

Acute stress is necessary for survival, and provided your stress levels go down after a small emergency is over, it does not affect our immunity or our long term health.

Chronic Stress

This is the version of stress that affects immunity. Chronic stress is what happens when your body is in fight or flight mode so often, it gets stuck in that mode. This doesn't mean you feel stressed nonstop, only that you feel stressed often enough that your body doesn't have time to revert to its normal state of being before the next bout.

Chronic stress can be caused by anything, from hating your job to a bad relationship to sitting in traffic for hours a day. It affects your mind and your body, because you are overproducing cortisol and other stress hormones to an extent that your body can't create enough "feel good" chemicals to balance those out.

Chronic stress is what affects your immune system, so from here on out, when we're talking about stress, we mean the chronic version of it, not the acute one.

Stress and Digestion

When we feel stressed, we don't digest our food well. That's because in periods of stress, our blood is focused in our muscles; but when we eat, we need adequate blood to go to our gut to digest our food. Accordingly, eating while under the influence of stress leads to poor digestion and nutrient absorption.

People with chronic stress can then end up deficient in many different nutrients, even if they eat healthfully. By not having the nutrients needed to be healthy, your body is less able to fight off illness.

Stress and Inflammation

Long term inflammation is a leading cause of illness, and stress causes inflammation. One study noted that "75%–90% of human diseases are related to the activation of stress system."

Chronic stress directly leads to systemic inflammation, in which our body is essentially attacking itself, and this process makes it more difficult for our bodies to ward off illness.

Stress and Infection

Long term stress increases our chances of a life-threatening infection. In fact, studies have shown that stress plays a part in nearly every situation of life-threatening infection, with one study concluding that "stress related disorders were associated with all studied life threatening infections." Even though stress leads our body to attack itself, it may not specifically attack the infection properly.

Stress and Disease

Stress can often lead directly to disease. It suppresses our T cells, which ward off illness, and therefore doesn't let our immune system work well at large. Stress increases the risk of diabetes, worsens asthma, and increases the potential to develop ulcerative colitis, just to name a few of the serious maladies it can cause. It can even lead to plaque buildup in arteries, which causes heart attacks, and it can make psychiatric problems worse.

Stress and Illness Recovery

Not only does stress cause illness, it also inhibits your ability to then recover from it. Stress is directly correlated to worse outcomes for wound healing, and it can actually slow healing down, with studies showing that it directly causes the healing process to take longer than it otherwise would.

This means that not only can stress cause you to get sick, it can then also make it more challenging for you to recover and become well again.

Self-Care Strategies

As you can see, stress can be detrimental to our immune systems, leading to everything from infection to major disease. The best thing you can do to prevent stress from hurting your immune system is manage your stress. There are countless ways you can do this. The following are the easiest, least expensive, and most straightforward methods of managing your stress.


Physical wellbeing can help us with assorted mental health issues, such as anxiety, and it can help prevent mental health issues from developing. Exercise causes our body to produce feel good chemicals, which are basically the opposite of stress hormones.


Unhealthy foods may feel like they help us become less stressed because in the short term, they're enjoyable and can flood our body with serotonin. But in the long term, most unhealthy foods can contribute to inflammation, which can then lead to illness.

On the other hand, eating a diet rich in healthy foods helps to give our bodies the nutrients it needs to fight stress. Some nutrients, such as omega-3, which is found most prevalently in wild fish, serve to help our bodies fight stress.

Practice Mindfulness

Mindfulness is an impactful way to lower your stress levels. By focusing on the present and being in the moment, you can help yourself relax and talk yourself down from stressful situations. And by not spending so much time in your head worrying, you can do less conceptual stressing about the future or troublesome situations that you can't control.

Starting the practice of mindfulness is as easy as just learning how to pay attention to yourself and your immediate surroundings.


It might sound like a new age technique, but breathwork actually has proven health benefits, and they work on people of all ages. The simple act of slowing down our breath slows down our nervous system and our heart, making our body on the whole better able to function.

There are many different types of breathwork, but you can begin with the act of just focusing on your breathing and slowing it down, to reap stress-related benefits.


Therapy is useful for stress in many ways. It can help you deal with it through talking with a professional, and also can provide you with additional modalities to cope with it. There are many specific types of therapy that can be useful for stress, from EMDR to hypnotherapy, but it can also be useful just to have a professional to talk to about the things that make you feel stressed and how you can cope with them.

A Word From Verywell

Knowing that you need to take steps to manage your stress can feel, well, stressful! Know that it can take years of unmitigated stress for problems to occur, and what matters most is that you are starting on the path of stress reduction now.

9 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Konturek PC, Brzozowski T, Konturek SJ. Stress and the gut: pathophysiology, clinical consequences, diagnostic approach and treatment options. J Physiol Pharmacol. 2011 Dec;62(6):591–9.

  2. Lopresti AL. The effects of psychological and environmental stress on micronutrient concentrations in the body: a review of the evidence. Adv Nutr. 2020 Jan;11(1):103–12. doi:10.1093%2Fadvances%2Fnmz082

  3. Liu YZ, Wang YX, Jiang CL. Inflammation: the common pathway of stress-related diseases. Front Hum Neurosci. 2017 Jun 20;11:316. doi:10.3389%2Ffnhum.2017.00316

  4. Song H, Fall K, Fang F, Erlendsdóttir H, Lu D, Mataix-Cols D, et al. Stress related disorders and subsequent risk of life threatening infections: population based sibling controlled cohort study. BMJ. 2019 Oct 23;367:l5784. doi:10.1136/bmj.l5784

  5. Salleh MohdR. Life event, stress and illness. Malays J Med Sci. 2008 Oct;15(4):9–18.

  6. Gouin JP, Kiecolt-Glaser JK. The impact of psychological stress on wound healing: methods and mechanisms. Immunol Allergy Clin North Am. 2011 Feb;31(1):81–93. doi:10.1016%2Fj.iac.2010.09.010

  7. Christian LM, Graham JE, Padgett DA, Glaser R, Kiecolt-Glaser JK. Stress and wound healing. Neuroimmunomodulation. 2006;13(5–6):337–46. doi:10.1159%2F000104862

  8. Madison AA, Belury MA, Andridge R, Renna ME, Rosie Shrout M, Malarkey WB, et al. Omega-3 supplementation and stress reactivity of cellular aging biomarkers: an ancillary substudy of a randomized, controlled trial in midlife adults. Mol Psychiatry. 2021 Jul;26(7):3034–42. doi:10.1038/s41380-021-01077-2

  9. Zaccaro A, Piarulli A, Laurino M, Garbella E, Menicucci D, Neri B, et al. How breath-control can change your life: a systematic review on psycho-physiological correlates of slow breathing. Front Hum Neurosci. 2018 Sep 7;12:353. doi:10.3389%2Ffnhum.2018.00353

By Ariane Resnick, CNC
Ariane Resnick, CNC is a mental health writer, certified nutritionist, and wellness author who advocates for accessibility and inclusivity.