Can Stress Affect Your Immune System? Experts Break It Down
Stress (and the overwhelm and anxiety that often come with it) is bad enough on its own, but can it actually make you sick? We talked to the experts to get the lowdown on the relationship between chronic stress, illness, and lingering physical symptoms.
Can stress make you sick?
The short answer is: sort of. While stress doesn't directly cause sickness, it can have a negative impact on your hormones and weaken your immune system's defenses, which makes you more likely to get sick.
Chronic stress (coupled with inadequate sleep) is the most common reason people get sick, Heather Moday, M.D., an allergist and immunologist, previously told mbg. "When we are run down and cortisol soars, our virus surveillance cells dip and we get sick more easily," she explains. "Cortisol itself interferes with the ability of specific white blood cells called T-cells to proliferate and get signals from the body. In addition, cortisol also lowers an important antibody called secretory IgA, which lines the respiratory tract and gut and is our first line of defense against invading pathogens."
Inflammation plays a role, too. Researchers from a study that was published in the Proceedings of the National Academy of Sciences found that stress can negatively affect the way your body handles inflammation. When you're stressed, your body releases a hormone called cortisol. Cortisol helps regulate inflammation and, in normal amounts, is actually considered anti-inflammatory1. But when you're stressed all the time, your cortisol levels stay elevated, and this can eventually decrease your body's sensitivity to the hormone, according to Sheldon Cohen, lead researcher for the study. As a result, your body, and your immune system, don't respond to cortisol as they should.
Instead, inflammation gets turned on and then stays on, an issue that can make you more susceptible to getting sick—or at least experiencing symptoms. Cohen explains that when you get symptoms of a sickness, like the common cold, they aren't necessarily caused by the virus itself but rather a "side effect" of the way your body handles the inflammation associated with exposure to pathogens. And the greater the inflammatory response, the sicker you feel.
To test this theory, Cohen exposed 276 healthy adults to a virus that causes the common cold. After five days, he found that the participants who were under the most stress, and thus had an impaired ability to properly regulate inflammation, were the most likely to develop symptoms.
In a follow-up study, Cohen exposed 79 participants to the cold virus once again, but this time he measured the amount of inflammation that occurred after exposure. The participants who were under the most stress had greater levels of inflammation following exposure to the virus, which meant more severe symptoms.
The takeaway was that your immune system's ability—or inability—to regulate inflammation plays a major role in whether you will get sick and how severe the symptoms may be.
When you're stressed, you're also more likely to lean toward unhealthy coping mechanisms, like overindulging in "comfort foods" that are high in sugar or refined carbs (you can learn more about the impact of those foods here), smoking, and drinking in excess—all behaviors that increase the chances of getting sick.
8 ways stress can cause physical symptoms.
While that's a big problem, it's not the only problem associated with stress. In addition to increasing the likelihood that you'll catch the next bug going around, chronic stress can also cause some gnarly physical symptoms:
If you've ever been under a lot of stress, you probably don't need anyone to tell you that headaches can develop as a result, but just in case: "One of the most common physical reactions to stress is the tensing of muscles, which can ultimately trigger tension headaches, migraines, and other musculoskeletal conditions," says Isaac Eliaz, M.D., M.S., LAc, founder and medical director of Amitabha Medical Clinic.
In addition to headaches, tense muscles can lead to widespread muscle pain. This pain can affect all parts of the body, but the neck and shoulders are common places where people hold tension2. Facial pain3, specifically in the ears, teeth, and head, can also develop as a result of stress (and likely jaw clenching that comes with it). Plus, there seems to be a correlation between stress and pain sensitivity, meaning that when you're feeling really stressed out, things just seem to hurt more.
When it comes to sleep, stress is a double-edged sword. Chronic stress can lead to insomnia and sleeping troubles, and lack of proper sleep can increase the body's stress response. Eudene Harry, M.D., medical director for Oasis Wellness and Rejuvenation Center, explains that when you're chronically stressed, you're in a constant state of high adrenaline, which makes it difficult to wind down and get the sleep you need.
If you're not sleeping well because of stress, you'll likely feel tired pretty often. But chronic stress can cause fatigue that's not alleviated by rest or sleep. One study found that a high level of stress can lead to "unexplained" fatigue4. This type of stress fatigue can also lead to impaired performance and function throughout the day. Translation: It's harder to get basic tasks done and/or focus on your work. That's because chronically high levels of cortisol can deplete your adrenal glands, which makes you feel like you're running on empty, according to Lissa Rankin, M.D.
Stress may not directly lead to blemishes, just like it doesn't directly cause you to get sick, but it can increase the severity or trigger an onset of skin issues. Researchers from an older study published in JAMA Dermatology looked at a small group of 22 participants, and even when controlling for other breakout-causing factors, like lack of sleep and poor diet quality, they found that increases in stress were positively correlated with more severe skin concerns5.
Digestive discomfort and stomach pain
Like headaches, digestive issues and stomach pain are some of the most common physical symptoms of stress. "Our stomach and intestines have their own unique nervous system called the enteric nervous system," holistic psychologist Nicole Lippman-Barile, Ph.D., previously told mbg. "These nerves respond to the same stress hormones and neurotransmitters that our brains do."
"Stress is also hard on your digestive system, as it affects which nutrients your intestines absorb, influences how quickly food moves through your body, and can provoke you to eat more or less than you normally do," says Eliaz. "In turn, this can cause nausea, pain, vomiting, heartburn, constipation, acid reflux, and/or diarrhea."
When you're stressed, the brain releases a neurotransmitter called acetylcholine6 (ACh). ACh activates the nervous system, which sends signals to the sweat glands that increase sweating all over the body but especially on your palms, soles, face, and underarms.
Increased heart rate
When you're under stress, the release of cortisol and adrenaline triggers the "fight or flight" response, which increases the contractions in your heart muscles and, as a result, your blood pressure and heart rate. If stress is chronic, your blood pressure and heart rate can stay elevated for an extended period of time, which can increase your risk of developing more serious problems.
How to support mental & physical health.
Stress is an unavoidable part of life. You're never going to be able to get rid of it completely, but it's important to find ways to manage it and to increase your body's resilience—or ability to handle stress. When you do, you may find that your physical symptoms start to dissipate, or even go away completely.
Here are some things you can do to support both your mental well-being and physical health:*
- Try yoga and meditation: Yoga can balance your nervous system7 and hormones while also reducing cortisol8, blood pressure, and inflammation. Meditation helps improve the way you respond to stress9, which can ultimately lower cortisol and inflammation, too. One study that was published in PLOS One found that people who participated in stress reduction programs like yoga and meditation had a 43% drop in medical visits the following year.
- Exercise: Beyond yoga, exercise can improve emotional resilience10, or the way you respond to stress. It also produces endorphins, happy chemicals that decrease tension, improve sleep, and just make you feel better overall.
- Consider adaptogens: Adaptogens are herbs or supplements that support your adrenal glands and improve the way your body physically responds to stress11. Some examples include ashwagandha, Rhodiola rosea, Asian ginseng, and Eleuthero.*
- Drink tea: Drinking tea can lower your cortisol levels and help you recover from stress more quickly. In addition to black tea, you can try sipping on chamomile, lavender, ginseng, catnip, or lemon balm herbal tea.
- Limit caffeine: While caffeine does have some positive benefits, it can spike cortisol levels12 throughout the day and negatively affect sleep duration and quality by as much as 40%. If you're under a lot of stress, it may be best to completely cut out caffeine, but you can also try cutting back to see how that makes you feel.
- Experiment with other supplements and herbs: Kava kava, hemp oil, L-theanine, valerian root, magnesium, and hops have all shown positive effects on stress and the physical signs that come with it. In addition to other stress-reduction techniques, you can incorporate these into your daily routine (after checking in with your doctor first).*
Stress won't necessarily make you sick, but it can weaken your defenses and promote inflammation, which can make you more likely to get sick. Nagging physical symptoms, like tension headaches, digestive issues, and increased sweating, often come hand in hand with stress, as well.
If you're under a lot of stress, you won't ever be able to get rid of it completely, but you can manage and learn to better deal with it with things like yoga, meditation, regular exercise, and some targeted supplements (find our favorites for immune support here!). In addition to managing your stress, it never hurts to support your immune system on a daily basis for extra assistance.
Of course, it's always a good idea to chat with your doctor about any lingering physical symptoms to rule out any other underlying causes.
Lindsay Boyers is a holistic nutritionist specializing in gut health, mood disorders, and functional nutrition. Lindsay earned a degree in food & nutrition from Framingham State University, and she holds a Certificate in Holistic Nutrition Consulting from the American College of Healthcare Sciences.
She has written twelve books and has had more than 2,000 articles published across various websites. Lindsay currently works full time as a freelance health writer. She truly believes that you can transform your life through food, proper mindset and shared experiences. That's why it's her goal to educate others, while also being open and vulnerable to create real connections with her clients and readers.