Stress and the Immune System

Stress is a part of life. At some point or another, everyone experiences it. But aside from how it makes you feel, how does it affect your immune system and overall health? 

Perhaps you’ve noticed some of its effects firsthand. After you wrap up a big project at work, it feels like you’ve been running on coffee and adrenaline alone for weeks. When you cross the finish line, you want to celebrate, but you end up sick, depleted and unable to leave the house. It’s not just mental anymore. It’s physical. Or perhaps, during a stressful breakup, the Universe added insult to injury and gave you a nasty cold on top of your heartache. 

The Link Between Stress and Immunity

If you’ve noticed a link between stress and sickness before, it’s not just in your head—stress directly affects your immune system in both the short- and long-term.

This guide will help you understand the link between stress and immunity. Armed with this knowledge, you’ll be able to develop healthy habits, combat nervousness, and boost your overall health. 

The Body’s Stress Response

You already know the physical symptoms of stress. In any stressful situation, you’ve probably experienced some variation of the below:

• A racing heart
• Sensations of hotness
• Sweaty palms
• Tightness in your chest
• Shallow breathing
• Restless sleep
• Tension headaches
• An upset stomach, vomiting, or diarrhea

What physiological changes create these unpleasant sensations? According to the American Psychological Association, the symptoms we associate with stress often begin with a nervous system response. This response then affects our organ systems and bodily functions. Thus, when we become nervous due to a real environmental threat or our own thought patterns: 

• The autonomic nervous system (ANS) perceives a potential threat, and the “fight or flight” response kicks in. 

• The ANS sends signals to the endocrine system’s adrenal glands, which begin to produce the stress hormones cortisol and epinephrine (also known as adrenaline).

• Stress hormones and nervous system responses directly affect the cardiovascular system and the respiratory system, causing the heart to beat faster and breathing to quicken.

• As our blood vessels dilate, our muscles and other bodily systems including the digestive system and muscles are affected, too. This is where symptoms like an upset stomach, sweatiness and even headaches can come in.

As you already know from your own experience, stress can wear on the mind and body. 

This is because of its fast impact on all of our bodily systems. Luckily, when it comes to acute stress, these feelings can be very short-lived. Once the stressor goes away—your interview is over, or you get off a roller coaster ride—the body is able to return to a balanced state of homeostasis.

However, prolonged stress can impact immunity. In fact, even a stressful few days can have an effect. In the 1990s, researchers Janice Kiecolt-Glaser and Ronald Glaser conducted a long-term study that found medical students’ immunity were impaired after just three days of exams. 

The longer a period of stress, the more potent an impact it can have on the body. In the case of chronic stress, it may become difficult to go back to normal over time.

Chronic Stress and Health

While occasional nervousness and jitters are a part of almost everyone’s life, chronic stress develops when the body is unable to return to homeostasis—when you enter a state of stress and are unable to escape it for days, weeks, or even months at a time. According to the Mayo Clinic, long term exposure to stress hormones cortisol and adrenaline can cause:

• Depression
• Persistent anxiety
• Difficulty with digestion
• Headaches
• Restless sleep
• Inability to concentrate
• Heart disease

While heart disease may seem like the most serious effect of stress, it’s important to note that impaired immunity is a serious problem, too. A poorly functioning immune system can make you more susceptible to all kinds of illness over time.

How Stress Impacts the Immune System

Your body’s immune system is made up of several organs, as well as cells that travel throughout your bloodstream. The immune system includes:

• The thymus, spleen and lymph nodes
• Your gut (the gut-associated lymphoid tissue) and GI tract
• Lymphocytes: B-cells and T-cells are white blood cells that can directly combat infection 

The immune system is intimately linked to the nervous system. In the European Journal of Physiology, Luciana Besedovsky and her colleagues explain that there is 

“A bidirectional communication between the central nervous and immune system which is mediated by shared signals (neurotransmitters, hormones and cytokines) and direct innervations of the immune system by the autonomic nervous system.”

To put it more simply, the nervous system and the immune system communicate with each other, and the nervous system directly communicates with the immune system to regulate its functions.

When your body experiences a stressor, your immune system immediately kicks into high gear. As your autonomic nervous system starts responding to a perceived threat, your immune system receives the signal to prepare and fight off disease. Therefore, it can seem counterintuitive that, over time, stress actually decreases immunity and makes your body more vulnerable.

How does this work? 

When the nervous system is in a heightened state of stress, the immune system is directly impacted in several ways. Jennifer Morley and her colleagues explain the mechanisms in Current Opinion in Psychology:

• Immune cells may not effectively receive signals from the nervous system during times of stress.

• Some of the proteins released into the body during stress, called cytokines, create inflammation. While inflammation can fight pathogens in the short term, over time they create chronic inflammation, which negatively affects the immune system.

• During times of stress, latent viruses in the body can re-emerge as our immune systems lose control over them. That’s why a case of childhood chickenpox may reappear as shingles during a period of stress in adulthood.

Our normal, healthy responses to stress take a toll on the body over time. This is due to the immune system being flooded with inflammatory chemicals and weakened signals. This makes it harder to combat latent viruses and new threats.

Sleep, Stress, and Immunity

Sleep is another important part of the puzzle when it comes combating the negative effects of stress on our immune systems. Are you unable to get to sleep, tossing and turning with anxious thoughts as you try to drift off? That lack of sleep affects your immune system, too. 

A chronic lack of sleep can lead to:

• The under or over-production of cytokines (which fight off disease and create inflammation)

• Decreased functionality of your immune system’s T-cells, which do their best work at night.

• Increased cortisol levels and difficulty regulating blood sugar, which can lead to inflammation and disrupt gut health.

That’s why Dr. Kimberley Hardin tells Healthline that “Sleep is like anything else in the body. It’s a natural state and has to be taken care of to be healthy.”

Gut Health and Immunity

Long-term stress affects the gut just as much as every other organ. There's a reason why you may feel an upset stomach (or a pain in your gut) when under acute stress: Harvard Medical Publishing explains that “the brain and the gastrointestinal (GI) system are intimately connected.”

Why is this important to immunity? 

It’s because your GI tract is part of your immune system. Your gut-associated lymphoid tissue interacts with your gut microbiome, the collection of bacteria that live inside your GI tract. Your gut plays a role in processing crucial nutrients, regulating blood sugar and more. When your nerves upset your stomach, they can also upset this delicate ecosystem—and your immunity.

When you’re under chronic stress, it can be difficult to maintain a healthy diet. You might soothe yourself by eating junk food, or you might be too stressed to eat at all. Combined with the effects of stress hormones, this can upset your gut balance and disrupt your immune system even more.

Combatting Stress

While you already know that stress is unpleasant in the short term, it’s clear from the evidence that it also has long term negative effects on the immune system. This is one reason why it’s so important to develop effective strategies for coping with and combating stress. 

Ways to manage stress include:

• Getting sufficient exercise - around 150 minutes a week
• Sleeping at least 7 hours a night
• Practicing meditation or mindfulness daily for about 30 minutes
• Eating healthy, balanced meals

However, in times of high stress, this might seem like a tall order. After all, if you’re unable to sleep, you might wake up in the morning unable to concentrate enough to meditate. You’re  also too tired to cook a proper breakfast, so you order delivery. Then, you feel more tired from that breakfast burrito, and the last thing you want it to go for a run. 

As you can see, stress can be a vicious cycle.

How CBD Can Combat Stress

If you’re looking for a way to naturally relieve tension and nerves, consider CBD. Cannabis has long been used to help people get adequate sleep and destress. Hemp-derived CBD can offer these same benefits without marijuana’s characteristic “high” effect. 

In fact, CBD is known to help people:

• Manage daily stressors 
• Find feelings of calm and relaxation
• Get restful sleep
• Maintain a healthy appetite

Why does CBD help with stress? It’s because of its effect on the Endocannabinoid System. The ECS is a system in our bodies made up of nerve receptors in the central nervous system and the autonomic nervous system. 

The ECS is thought to help regulate:

• Sleep
• Appetite
• Mood
• Memory
• Inflammation 

Since CBD binds with receptors in the ECS, it’s thought to promote the healthy regulation of ECS functions. Now that you know how important a role sleep, mood, appetite, and inflammation play in maintaining your overall immunity, it’s easy to see how CBD’s stress-busting effects could potentially boost your immunological response, too.

CBD can be applied topically or taken orally. CBD oil is a great option for incorporating CBD into your daily routine, promoting much-needed peace and relaxation. Our Nourish Body Lotion is another great option if you’re wondering how to fix dry cracked hands and skin. 

Plant People CBD

If you’re looking for a trustworthy source of hemp-derived CBD, look no further. Our CBD capsules are specially formulated with adaptogenic herbs to help soothe everyday stressors and, in turn, boost your immune system response. Organically grown in Colorado, our hemp is third party lab-tested to assure quality and consistency. 

At the end of the day, stress can affect your immune system. In fact, it can affect everything. The way you eat, your happiness, your ability to stay productive—these can all be negatively impacted by unmanaged stress. That’s why it’s important that you eat well, maintain a healthy sleep cycle, and do everything in your power to mitigate stress’ ramifications. 

Reviewed by Gabe Kennedy

 Co-Founder of Plant People, Gabe Kennedy is an acclaimed chef and entrepreneur. Growing up in a house of healers and herbalists, he is passionate about the power of food as a tool for health, and actualized this passion and belief system into his company, Plant People. Named to Forbes 30 under 30 Gabe has shaped menus and cooked his way around the world with his mission to promote a more communal, green and healthy world.

 Gabe is a graduate of The Culinary Institute of America and Cornell University School of Hotel Administration. You can learn more about his work at his website.