We’ve all been there. You’re trying to be a million places at once: getting ready for the holidays, shopping for the whole family, trying to finish up a major work project before the new year, the weather is getting colder, and then the cherry on top: you catch a cold.

If it feels like you always get sick at the “worst” possible time, when you have way too many things to worry about as it is, it’s probably not a coincidence. Stress and adrenal function have a huge impact on the immune system.

A number of studies over the years have shown that different kinds of life stressors, including high job stress, divorce or relationship struggles, and bereavement lead to decreased immune function and increased vulnerability to viruses and infections. And when stress is chronic, and adrenal function suffers, the problem can get even worse.

Every year, when winter starts to come knocking, I see a flurry of resources dedicated to how we can support immune function and ward off viruses. There is often good advice to be found there, including boosting our levels of key nutrients that we may be lacking, especially in the winter months (like vitamin D).

One thing I don’t see mentioned nearly enough? Supporting adrenal health! Adrenal fatigue or dysfunction is, in my experience, one of the most common reasons why the immune system is having trouble in the first place.

An immune system problem related to adrenal fatigue can mean more frequent viruses and infections, and a harder time recovering from them. It can also lead to an increased likelihood of developing certain kinds of chronic disease, which we’ll explore a little later on. Finally, if adrenal fatigue is interfering with immune system function, it’s a pretty solid bet that other areas of your health including hormonal balance, mood regulation, and metabolism are out of whack too.

We know that the adrenal glands, located atop the kidneys, are responsible for producing hormones related to our stress response. One of the key players is cortisol, often referred to as the “stress hormone”. Levels of cortisol that are too high or too low are a key indication that adrenal dysfunction is present.

Adrenal Fatigue, Cortisol, and Immune System Function

Since we often call cortisol the “stress hormone”, it’s not always clear how big of a role cortisol plays in other areas of our health. Cortisol is actually crucial when it comes to regulating the immune system! Levels that are consistently too high, too low, or off balance can lead to various immune system problems.

Let’s start by taking a basic look at how the immune system works. When the body detects an intruder– called a pathogen– the immune system gets to work on attacking it and protecting us from it. This involves creating inflammation, in part to signal that defense and repair is necessary.

It is this inflammatory response that leads to symptoms like a stuffed up or runny nose, sore throat, or a fever.

Because of its many links to chronic disease, we often think of inflammation as a dirty word, but inflammation is an absolutely essential component of a healthy immune response. We just want to make sure that somebody is regulating it and keeping it from becoming excessive, overreactive, or chronic.

This is one of cortisol’s jobs. When you have healthy adrenal function, balanced cortisol levels, and a healthy immune system, cortisol helps to reduce inflammation and keep levels in check during an immune response, without getting rid of it completely.

Cortisol levels that are too high or too low lead to either an underactive immune system and insufficient inflammation to protect us against viruses, infections, and other pathogens, or an overactive immune system and too much inflammation (which can lead to issues like autoimmunity and allergies). Of course, neither situation is good!

How High Cortisol Can Lead to More Viruses and Infections

Depending on how advanced your adrenal fatigue or dysfunction is, your levels of cortisol might be too high, or they might be too low. These two states of imbalance are both problematic for the immune system, but in different ways.

Usually, in the earlier stages of adrenal fatigue, our stress response system is very busy (just like us)! Our adrenals are working overtime to combat a heavy load of stressors, from the emotional to the physical to the environmental, and this includes producing a ton of cortisol.

I mentioned earlier that one of cortisol’s roles is reducing and managing inflammation during an immune response. The thing is, when cortisol levels are really high the way they are in the early stages of adrenal fatigue, inflammation is reduced too much, and the immune system is suppressed to the point of not really functioning properly.

Basically, when we encounter stress, cortisol and the rest of our hormonal team are thinking this: something really challenging is going on, and we need all hands on deck! Let’s just move some of our resources away from the immune system (and the digestive system, and the reproductive system) for a bit while we take care of this problem.

Seems reasonable on its face, but the problem is that when high stress becomes chronic, and stressors aren’t just being taken care of and then disappearing, our stress hormones don’t have the chance to return everything back to normal. With all of the modern stressors we face, it’s really common for cortisol levels to just stay high, which means that immune system function stays low.

This makes us more susceptible to colds, the flu, and bacterial infections. It also helps to explain why we often get sick at that “worst” time– stress itself is making us more vulnerable to illness.

High cortisol levels can also make it more difficult for us to recover from viruses and infections– my patients often tell me that their colds seem to linger on forever.

How Low Cortisol Can Lead to Autoimmunity and Chronic Illness

As adrenal dysfunction progresses, certain things start to change. While you may once have been producing way too much cortisol in an attempt to battle high levels of stress, your adrenal glands and the rest of your stress response system might now be exhausted and unable to produce even the amount that you need.

We know that high cortisol levels suppress the immune system. So wouldn’t low cortisol levels actually lead to a boost in immune function?

The answer is… kind of! But the problem is, when cortisol levels get too low, we are actually removing the watchman that keeps an eye on inflammation during an immune response. Basically, the immune system and inflammation are left to run wild.

When nobody is monitoring it, and the immune system is left to its own devices, a number of new problems can arise. This is the time for us to use “inflammation” as a dirty word again. Inflammation can become problematic and chronic, which can lead to a number of illnesses including fibromyalgia and Chronic Fatigue Syndrome, mood disorders and depression, and obesity, to name a few. It can also lead to autoimmune disease (autoimmunity occurs when the immune system attacks the body’s own healthy cells and tissues) and the development of allergies, also characterized by an overactive immune system.

How to Naturally Support Adrenal & Immune System Function

Adrenal fatigue is one of the most common things I see in my practice, and this often comes with symptoms and concerns related to faulty immune system function. Some patients feel like they’re just getting sick all the time, many have a really hard time recovering when they do catch a cold or get an infection, or the infection keeps coming back. I also see a lot of autoimmunity, food allergies or sensitivities that were not present earlier in life, and digestive concerns including leaky gut and dysbiosis (an imbalance in gut bacteria). All of these issues are related to issues with the immune system caused in large part by adrenal dysfunction.

What bothers me to no end is hearing about how many of these patients have been treated for these issues. So many doctors are prescribing medication after medication– or doling out antibiotics like they’re candy– which just creates more stress and inflammation, and doesn’t get to the root of the problem.

Of course, antibiotics and other medications are sometimes necessary, but my point is that we shouldn’t be overlooking the root cause.

When we see signs of immune system dysfunction of any kind, we should start thinking about and supporting adrenal function! I also firmly believe that adrenal support should be included when we talk about immune-boosting protocols during the colder months.

Natural support for immune system and adrenal function may include the use of adaptogens, a category of powerful herbs that have been found to help regulate the stress response and manage cortisol levels. Adaptogens that may help with adrenal fatigue include rhodiola, maca, eleuthero, and ginseng.

Certain vitamins and nutrients can also be very helpful here. Vitamin C is essential for both adrenal and immune system function, and levels have been shown to decrease during stress. B vitamins and magnesium are also crucial.

As with all supplements, it’s smart to consult with a practitioner and determine what specific protocol is best for you.

Choosing whole, fresh, anti-inflammatory foods is extremely important, as well as finding ways to bring more relaxation, calm, and mindfulness into your life. Although there are many herbs, nutrients, and other supplements that can be very helpful for adrenal function and immune system function, you can’t supplement or even eat your way out of adrenal fatigue. It requires really digging into your stressors, and finding ways to reduce levels of stress in order to heal.

High stress might be common in the modern age, but I don’t think we should just accept it. It shouldn’t be “normal” to be so stressed out that your body, hormonal system, and immune system can’t function properly. Consider this a prescription for self-care!

I highly recommend working with a functional medicine practitioner who will help you to get to the root of your adrenal dysfunction, hormonal imbalances, and immune system dysfunction, and support true healing rather than offering you a band-aid “solution”.

I hope that with this deeper understanding of how the immune system, the adrenals, and hormones like cortisol are all intertwined, you will have a better idea of what to investigate, and how to move forward towards recovery.

Reviewed by Dr. Mark Menolascino, MD

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