Can ‘adrenal fatigue’ be the answer to unexplained symptoms of fatigue and tiredness? Let’s break down what the science says on what it is, and isn’t.


Adrenal fatigue is a term that has been circulating around the wellness world for years. It’s especially common in the realm of functional and integrative medicine, but it’s also something you may have heard of while browsing the internet or reading a book. 

While it’s a theory used to explain symptoms of low energy and tiredness, many medical professionals often question whether adrenal fatigue is actually real. 

So what is “adrenal fatigue”?

The adrenal glands are the last part of our hypothalamic pituitary adrenal (HPA) axis. Your HPA axis is responsible for your stress response, also known as your fight-or-flight response.  These two small glands sit on top of the kidneys and produce a variety of hormones, one of which is cortisol. 

When your body experiences stress, the adrenals produce and release small amounts of cortisol into the bloodstream. This helps regulate blood sugar levels and metabolism, reduces inflammation, and regulates memory formation.

In times of stress, however, cortisol increases heart rate, blood glucose, respiration, and muscle tension. Cortisol also shuts down the body’s systems that aren’t necessary in times of crisis. You need cortisol to survive.

The term adrenal fatigue is often used in the media and by functional medicine clinicians to describe a condition in which someone experiences chronic, repeated exposure to stressful conditions. The repeated exposure of stress over time causes overstimulation of the adrenal glands which, eventually, may fail to function as they should.

So what are the symptoms of “adrenal fatigue”?

The two most common symptoms associated with adrenal fatigue are tiredness and low energy. Other symptoms include brain fog, lack of motivation, depressed mood, and having trouble getting out of bed despite getting an adequate amount of sleep.

Because these are such generalized symptoms that can be associated with many potential medical problems, it makes it challenging to nail down a specific diagnosis. Anemia, autoimmune diseases, thyroid problems, mood disorders, problems with major organs, infections, and sleep disorders are all associated with low energy and fatigue. 

Even if you visit a health care provider to perform a physical exam and order diagnostic tests, it often comes back inconclusive and lends few, if any, answers. This can be perplexing and frustrating for you as the patient, as well as for the health care provider because there are no clear cut answers for the symptoms you’re experiencing.  Hearing, “There’s nothing wrong with you” or “It’s all in your head” can be even more frustrating and invalidating as a patient. 

And that is when the theory of “adrenal fatigue” becomes enticing to explain your generalized symptoms of fatigue and low energy.

So what does the actual research say?

A systematic review was published in 2016 which explored the validity of adrenal fatigue. The review published included 58 studies and found no evidence for the diagnosis of adrenal fatigue. As of now, there are no formal criteria to define what adrenal fatigue is, nor is there an appropriate criterion to diagnose adrenal fatigue. 

There are also no valid tools for assessing adrenal fatigue. While there are lab tests used in the naturopathic or functional medicine settings that are marketed towards adrenal fatigue, it’s important to know that there is no compelling data to validate these tests. The same can be said about any hormone or food allergy tests marketed for this purpose. Just because a test is offered, doesn’t mean its claims are valid.

Another important distinction is that adrenal fatigue and adrenal insufficiency are not the same. Adrenal insufficiency is a well-researched and legitimate medical condition that has defined symptoms and can be diagnosed with laboratory tests.

The bottom line: your symptoms are real, but adrenal fatigue is not.

While it can be frustrating and emotionally-draining to experience these symptoms without a diagnosis or biological explanation, know this: your symptoms are real, and what you feel is real.

It can also be a good time to check in with your mental health, as anxiety and depression can often manifest symptoms similar to those associated with adrenal fatigue.  This is especially true in today’s fast-paced society, so take a step back and ask yourself: 

What are the stressors in my life? How is my sleep hygiene? How is my mental health and emotional health? Is the exercise I engage in helping me live a less stressful or more stressful life?

Remember, stress is real and can definitely affect your health, mentally and physically.

However, the cause isn’t due to adrenal fatigue – it’s not a real diagnosis. 

Adapted from the original post.

Robyn Nohling, FNP-BC, RD is a Registered Dietitian and Family Nurse Practitioner who believes that eating cupcakes and kale are both equally healthy to the body and mind. With a passion for women’s hormonal health and nutrition, Robyn cuts through the irrational noise of diet fads and unrealistic beauty expectations to help others find joy in food as it’s meant to be celebrated. Learn more about Robyn at The Real Life RD.

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