Tired AF: 7 Potential Sources of Fatigue

Remember back in college when you used to be able to stay out all night having fun with friends and then wake up early and make it to your 8 am class, no worse for the wear? Or, when you used to be able to watch your favorite Netflix shows without falling asleep midway through?


There’s tired, and then there’s tiiiiiiirrrrrred. If you’re a woman, chances are you’re finding yourself in the latter camp. Fatigue is one of the top health issues that women are struggling with.


And, maybe it’s not just you that has noticed your fatigue. A lot of women tell me about how their lack of energy is impacting their careers, their romantic relationships, friendships, and the time spent with their children.


The days of pulling all-nighters and Netflixing feel long behind you now. Most of the time it seems that you can’t even get your eyes open without a cup (or two) of strong coffee. Sometimes you make it through your day feeling like a zombie. Other days it feels like you could literally get back in bed and go to sleep.


How did this happen to you? You’re a woman in her prime with too much to do and too little time to do it. You crave the energy, the zest, and exuberance that you used to have and need to find a way to get that back.


Potential Causes of Fatigue


It can be challenging to pinpoint the root-cause of fatigue because there are so many potential things that can trigger this in women. I’ve put together a list of the most common causes of fatigue that I see in my practice, as well as what tests can be used to find out where your energy levels are being sabotaged.


1.) Poor sleep

Call me Captain Obvious if you like, but as Americans we have a serious sleep problem. Our society is go-go-go and there can be a lot of guilt that goes along with making time for adequate, quality sleep. Although there is individual variance in the ideal amount of sleep that you need, the general consensus is 7-9 hours of actual sleep. In order to achieve this, you should be getting into bed early enough to allow you time to fall asleep and hit those time marks before your alarm wakes you up. Having trouble falling asleep or staying asleep? Skip ahead to the section on HPA-D.


Sleep isn’t all just about quantity. It could be that your sleep quality is the source of your fatigue.


2.) Anemia

This is one of the potential sources of fatigue that your primary care is likely to bring up when you visit them. Anemia is when you don’t have enough healthy blood cells and there are a variety of factors that can contribute to this including nutrient deficiencies and excessive blood loss.


Testing: The best test to determine if you have anemia is a Complete Blood Count (CBC). This test will look at the number of red blood cells that you have and also analyze whether or not those cells are healthy. Here are some of the key markers tested with what normal levels could be for women (men have different normal levels):

  • Red Blood Cell (RBC) Count < 4million
  • Hemoglobin (Hb) < 12
  • Hematocrit (Hct) <37%
  • Mean Corpuscular Volume (MCV) 80-100
  • RBC Distribution Width (RDW) 11.5-14.5%

When I examine my clients CBC labs, I am looking for indications that they may be low in iron, folate, and/or vitamin B12. These nutrients are critical for healthy blood, and thus our energy levels. There are additional lab markers I often like to request for my clients struggling with fatigue and those are homocysteine and FIGLU. These are sensitive markers for vitamin B12 and folate insufficiency and can be very helpful in determining whether your levels are optimized!

How did you develop anemia in the first place? There are any number of ways someone can develop anemia, however in my practice the most common contributing factors are poor digestion (specifically low stomach acid), digestive inflammation, and heavy menstruation.


3.) Thyroid

This is another potential source of fatigue that your doctor is likely to bring up. Unfortunately, most doctors only test their patient’s thyroid stimulating hormone (TSH) levels when evaluating thyroid function. This single marker doesn’t typically provide enough insight into how well the thyroid is functioning, and even patients with “normal” labs may be exhibiting hypothyroid symptoms.

Testing: I typically request that clients get a full thyroid panel completed to give us a picture of how the thyroid is functioning holistically. A full thyroid panel should include the below markers:

  • TSH
  • Free T3
  • Free T4
  • Reverse T3
  • Thyroglobulin antibodies (TAA)
  • Thyroid peroxidase antibodies (TPO)


Clients who are hypothyroid and on thyroid hormone medication are sometimes perplexed by continued hypothyroid symptoms, even after months of medication use and “normal” TSH. One reason that could be contributing to this is something called peripheral hypothyroid. Most commonly prescribed thyroid hormone replacement contains only synthetic T4 (check with your doctor if you’re not sure which kind of thyroid medication you are on). Peripheral hypothyroid is where your body is not converting the inactive T4 hormone to the active T3 hormone. It’s the active T3 that really does the heavy lifting, and if your levels are low you’ll be feeling it.


Your T3 levels can be optimized at least in part through strategic changes in diet and by reducing inflammation. If you’re ready to optimize your thyroid health book your initial consultation!


4.) HPA-D

Hypothalamus Pituitary Adrenal (HPA) Axis Dysregulation, or HPA-D, is a common source of fatigue, sleep disruption (not being able to fall asleep or stay asleep), low libido, brain fog, reduced exercise recovery, and poor stress tolerance. You may know it better as adrenal fatigue, although that name can be a little misleading depending on how it presents.

How can we get HPA-D? There are a number of different factors that can leave you vulnerable to HPA-D, but the ones that I see most commonly in my clients are chronic stress, chronic sleep deprivation, poor diet (including undereating and overtraining), and inflammation caused by toxins.

Testing: My absolute favorite test for HPA-D is called the DUTCH Test, which is an acronym for Dried Urine Test for Comprehensive Hormones. Here is a screenshot of a portion of that lab test analyzing cortisol and cortisone patterns:


Normally, your adrenal glands release the hormone cortisol in a specific pattern. This hormone helps to determine your sleep-wake cycle by peaking in the morning and gradually tapering off until it reaches its lowest levels when it’s time for you to sleep. Some of the clients I’ve worked with have had a normal shaped curve, but were outside of the optimal ranges – being either too low or too high in the amount of cortisol their adrenals were outputting. Other clients have had a completely distorted sleep-wake cycle where their cortisol isn’t following a normal pattern and it’s impacting their energy levels.


Want to order the DUTCH test to evaluate your HPA axis health? Let’s order that for you at our initial consultation!


5.) Leaky gut

Intestinal hyper-permeability, also known as leaky gut, may be the most common source of chronic inflammation contributing to fatigue. The lining of our gut is designed as a selective barrier – keeping food particles in while allowing nutrients out! When we experience leaky gut, the lining of our gut may become overly passive and allow food particles to escape and triggering an inflammatory immune response to these foods. This is essentially how we develop food sensitivities.

When we become sensitized to foods (note, this is a different immune response than the one involved in food allergies) things that we were once able to enjoy without issue, now produce inflammation when we eat them.

Determining which foods you are reacting too can be somewhat less than intuitive, because the inflammatory reaction we have to a food may be delayed by several hours, even days. Often times, the symptoms of food sensitivities are also non-specific – like fatigue, for example.

Testing: For clients whom I suspect have food sensitivities, I usually suggest a comprehensive food sensitivity panel that evaluates their unique immune response to commonly ingested foods. Based on the results of the test, I may suggest that you avoid the reactive foods for a period of time while we work to reduce inflammation and restore the lining of the gut.

Other potential factors contributing to leaky gut that I may explore for clients struggling with fatigue are gut dysbiosis (specifically yeast overgrowth) or toxins (especially reactivity to mold).


6.) Blood sugar imbalances

In my practice, this may be one of these least commonly detected sources of fatigue. Our pancreas is responsible for producing the hormone insulin which transports glucose from our blood to our cells for immediate use, or storage as need may be. If our pancreas doesn’t output enough insulin, or our cells become resistant to insulin, our blood glucose levels will become abnormal. You may be thinking “I’m not diabetic”, but there is a spectrum of imbalance that should be addressed by making changes in the diet and resolving inflammation. If you’ve ever experienced lightheadedness or irritability before its time to eat (you know, being “hangry”), if you crave sweets, feel shaky or jittery sometimes, or have noticed recent increases in how often you need to urinate, it’s possible that your body isn’t handling glucose optimally.

Testing: The most accessible tests for determining how well your body handles glucose, is the fasting blood glucose test. Because fasting glucose can only provide us a single snapshot, I typically also request that clients have their doctors assess their glycated hemoglobin (HbA1c) levels. HbA1c is a test that can tell us how well your body has managed blood glucose over the last 90 days, give or take. Here’s what normal ranges typically look like:

  • Fasting blood glucose < 100 mg/dL
  • Glycated Hemoglobin (HbA1c) 4-5.6%

Have you already completed these tests, and you don’t like your numbers? Let’s review your health through a Functional Medicine lens to uncover the source of inflammation.


7.) Depression

First, I’d like to say that depression can represent a complex intersection of mental, emotional, spiritual, and physical health. As a Functional Medicine Nutritionist, I help clients learn how their food environment may be contributing to symptoms inflammation such as depression. Anyone struggling with depression should contact a qualified mental health professional and notify their doctor.

Depression can present as fatigue for some clients and bringing balance to the body may help improve symptoms. Optimizing nutrition, inflammation status, and gut health can be a great compliment to the work that your doing with your therapist or doctor.


Testing: I typically suggest that client’s struggling with depression start with the Genova ION Profile which will show opportunities to improve amino acids and nutrients needed to promote healthy neurotransmitter levels, as well as point us towards potential sources of inflammation such as gut dysbiosis or heavy metal toxicity. Here is a sample of the portion of the test that evaluates neurotransmitters:


Here’s what these markers are evaluating:

  • Vanilmandelate (VMA): The main metabolite of norepinephrine and epinephrine.
  • Homovanillate (HVA): The main metabolite of dopamine.
  • 5-Hydroxyindoleacetate (5-HIAA): Serotonin metabolite.


Do you want to see a complete sample lab for the Genova ION Profile? Send me an email to get the full report!



Are you suffering from extreme fatigue? Which of these potential causes are you suspecting as the source of your lack of energy? Let me know in the comments below!


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