The Top 8 Causes of Fatigue

Fatigue is one of the most common complaints heard in a doctor’s office today, with 5-7% of patients listing fatigue as their chief complaint, and nearly everybody else mentioning it as a big factor in the way they feel. These numbers are grossly underestimated, I rarely see someone without fatigue listed in their Top 3 Complaints. Many people don’t realize that fatigue is a clinical problem, so they under-report it to their medical doctor. In my clinics I have taken health histories on 1000’s of patients, and I very rarely get any (adult) patients who DON’T list fatigue as a complaint, and it’s becoming more and more prevalent to see people in their teens and 20’s with fatigue as a primary or secondary health complaint.

Fatigue has a broad spectrum of severity, and it’s very personal and subjective. You could feel a little sluggish or you could feel like you have been hit by a truck. A ‘down day’ for you might be an ‘up day’ for someone else. You could feel tired for a day, a week, or you could feel tired every day for many years.

I have had so many patients who struggle to get out of bed to go to work or parent their children.

I’ve had patients who’ve said that their kids would come to their bedside when they needed something because they knew that’s where mom could be found. I’ve had (grown adult) patients who need their parents to help them get through a trip to the grocery store. I’ve had patients who need 3 days to recover after vacuuming the house.

This is a highly debilitating problem for millions of Americans every single day, and a moderately debilitating problem for tens of millions of others who are still functioning but just don’t have the energy they feel they should have, and it’s a huge problem. This list is not by any means all-inclusive, in fact it’s only scratching the surface of complexity, but the goal of functional medicine is to look for the CAUSE by looking at the underlying mechanisms, and this is a dang good start. Here are the Top 8 Causes of Fatigue.

1. Anemia(s)

Improper evaluation and management of anemia is incredibly common in today’s healthcare system, and anemia(s) are very common, that’s why it’s #1 on my list. Anemia(s) are problems with red blood cells - their quantity, size, and amount of hemoglobin. Hemoglobin is necessary to carry oxygen to cells, which is the mechanism for fatigue: low iron → low HGB → low oxygen to cells → hypoxia → low cellular energy production. It sounds simple, but anemia(s) can be very complicated. Most people have heard of anemia but they aren’t aware that there are microcytic and macrocytic anemias, hypochromic and hyperchromic anemias, anemia of iron deficiency, anemia of chronic blood loss, anemia of chronic disease….it’s actually quite complex, but it’s REALLY common, so it’s the first thing to rule out.

Besides “iron-deficient anemia”, another common form of anemia is “Pernicious Anemia”, or B12-deficient anemia. While it is fairly rare to be actually diagnosed as Pernicious Anemia, it’s not uncommon at all to have issues absorbing and using vitamin B12, which leads to methylation issues, detoxification issues, neurotransmitter imbalances, and of course, fatiguing issues.

Labs are crucial for proper management. Anemias can be fixed by trying to take more iron or more B12, but still - why was it low? Many times it’s an absorption issue, and certain things need to be optimized within the stomach like optimizing stomach acid to absorb iron.

2. Mitochondrial Dysfunction

Everyone somehow remembers from school that mitochondria are the “Powerhouse of the cell”.... But seriously, they are the powerhouse of the cell, they power all cellular functions, and our body is made up of trillions of cells, and mitochondria power the whole thing, so when you talk about energy and fatigue, you have to talk about mitochondria. Mitochondria are like your body’s battery system, and when the batteries are dying, you are losing energy. Your body has roughly 50 trillion cells. Each cell contains 400-4000 mitochondria, the highest concentration being found in the brain, heart, and liver - very energy-dependent organs. That’s an insane number of mitochondria to calculate!

Mitochondria use energy in the form of electrons and protons from food, specifically from carbohydrates and fat, and together with O2 (oxygen) generate energy in the form of heat, H2O (water), and ATP - which is the currency used by the cells to generate energy. In a given day, a 65 Kg adult produces over 150 Kg of ATP! This production of energy is also known as “metabolism”, so when someone talks about a fast or slow metabolism, they are talking about the mitochondria.

Mitochondria are fascinating, and really they could be this entire article, because they ARE THE ENERGY PRODUCERS. Poor diet damages mitochondria. Trans fats damage mitochondria. Too much sugar damages mitochondria. Blue light damages mitochondria. Anemia impacts mitochondria by decreasing the O2 provided. Heavy metals damage mitochondria. Mold damages mitochondria. Stress impacts mitochondria. Inflammation damages mitochondria. Everything. Is. Mitochondrial.

Exercise helps mitochondria. B vitamins, magnesium, glutathione, amino acids, vitamin C, CoQ10….these all impact the mitochondria and energy production pathways. A ketogenic diet really helps mitochondria. Intermittent or extended fasting helps mitochondria. Red light therapy helps mitochondria. Hot or cold therapy helps mitochondria. There are so many things that we know are good for us but we may not realize that it’s because of the impact on mitochondria!

Mitochondrial function can best be tested by Urinary Organic Acids, which looks for a buildup of metabolites in the urine indicating a dysfunction in metabolic pathways in the mitochondria, then combining that with serum markers like thyroid hormones, homocysteine, and more.

3. Poor Sleep

Sleep is the most obvious cause of fatigue. If you sleep poorly you are going to be tired, and we have likely all felt that mental and physical fatigue. If you chronically experience poor sleep, you will be chronically fatigued and your health will deteriorate. Many important functions of the body are performed while sleeping, like healing and regenerating tissues, rebuilding energy stores, detoxification - and many important functions are related to proper circadian rhythm, or sleep cycles. These critically important functions include hormone secretion (hypothalamic-pituitary axis), immune system function, metabolism, cellular function, and gene expression. For this reason, altered circadian rhythm and poor sleep is associated with most of our modern diseases, including diabetes, cardiovascular risks, obesity, mood disorders, diseases of metabolism and energy, and even cancer.

While you are asleep your body cycles through stages of sleep - stage 1, 2, 3, REM, and back through again. Stage 3 is what’s known as “deep sleep”. As you cycle through the stages you spend less time in deep sleep and longer time in REM, which is why you are more likely to have more vivid dreams closer to waking up. Many people can sleep 8-10 hours and still wake up and not feel rested, and this is often a sign they are not getting enough deep, restorative sleep.

We have a webinar on “How To Sleep Better.”, which gives some good habit suggestions to improve your sleep hygiene, and In our recent podcast episode “3 Ways to Control Light Exposure For Better Sleep” we discuss sleep cycles, circadian rhythms, and melatonin in detail and give you simple action steps to control light exposure to enhance your sleep.

4. Stress and Poor Adrenal Function

If you google search “fatigue” and are researching why the heck you are so tired, you are likely to come across many articles talking about adrenal fatigue, which is more properly termed HPA axis dysfunction.

Stress has become a normal part of life in today’s society. Chemical, Physical, and Mental or Emotional stressors create a physiological stress response that leads to inflammation of your cells and disrupt your hormone balance, specifically affecting your HPA Axis, or Hypothalamic-Pituitary-Adrenal axis. This hormone communication system (along with your thyroid) is largely responsible for your body’s energy production and regulation, and the workhorses of this system are called your adrenal glands. These walnut-sized glands, which sit on top of your kidneys, produce your body’s stress hormones including cortisol, DHEA, norepinephrine and epinephrine (or the name we are more familiar with - adrenaline). Cortisol specifically is your body’s main stress hormone.

When your adrenals are being overworked, they fatigue. At first they produce MORE stress hormones, which creates receptor resistance, but eventually they begin to produce less stress hormones, hence the nickname “adrenal fatigue”. The first step to balance stress hormones is to reduce mental or emotional stress through methods like meditation, prayer, exercise, grounding, mindfulness, or the best one - taking a vacation. This will take time, but gradually you will find that your stress response is changing, your energy is changing, and you are generally feeling less fatigue. In today’s world, if you are not actively reducing stress, it will catch up to you!

Supporting the adrenals with supplements can be magical for fatigue - IF THE CAUSE IS NORMAL, DAILY STRESS and you just need some stress support. This can be done with certain herbs like ashwaganda, rhodiola, adrenal cortex glandulars, vitamin C, and B vitamins. We often see great results with fatigue by simply supporting the adrenal glands and adding in a high-quality full-spectrum B vitamin complex. If someone is suffering from extreme adrenal issues there is almost ALWAYS an underlying cause like mold, a leaky gut, chronic toxicity, a hidden infection (see below), or something that is providing a constant, low-grade stressor to your body at all times without you knowing it.

5. Thyroid Imbalances

The thyroid gland regulates your body’s metabolism and energy and is closely related to the adrenal glands. In fact, the same hypothalamus-pituitary control tower has an HPT Axis - Hypothalamic-Pituitary-Thyroid axis. The thyroid can be either hyperthyroid - which means it is producing too much thyroid hormone, or hypothyroid - in which case it is producing too little thyroid hormone. HyPOthyroidism is more commonly a cause of fatigue, lethargy, weight-gain, thinning hair, body temperature imbalances, and general poor feeling of well-being.

The thyroid gland can be altered by many factors, shown in the image below.

As you can see, there are a lot of factors that can affect your sensitive thyroid!

Approximately 80-90%% of hypothyroidism is what’s called Hashimoto’s Thyroiditis. This is an autoimmune condition in which your immune system actually begins attacking your thyroid tissues, causing further inflammation and poor thyroid function. Sometimes the key to proper thyroid function isn’t the thyroid gland at all, but other causes such as leaky gut or intestinal dysbiosis. IT IS CRUCIAL TO HAVE PROPER THYROID TESTING TO DETERMINE WHERE THE REAL PROBLEM IS!

Conventional medicine will determine thyroid diagnosis based on very limited testing of what is called Thyroid Stimulating Hormone, or TSH. This is horribly inadequate! A proper thyroid panel will (at least) include markers like T4, T3, T4 (free), T3 (free), Reverse T3 (rT3), T3 Uptake, and antibodies TPO and TG to determine whether the immune system is attacking the thyroid. Watch my Thyroid Disease Webinar to learn about the thyroid, its pathways, what testing you need to have, and how you can support it. I have a lab result sitting in front of me right now that a conventional endocrinologist would likely say “your thyroid is fine”, but with further testing we discovered severe inflammation and antibody levels (meaning that the immune system is attacking the thyroid) that are 7x the upper limit! Synthroid is one of the top-selling drugs in America, and millions are told they need a medication without truly knowing where the problem lies. It’s crucial to get the right testing to know so you can address the underlying functional issue.

6. Gut Dysbiosis

Your gut is populated by hundreds of trillions of microorganisms (bacteria, viruses, fungi, etc) which make up the environment known as your gut microbiome. These bacteria are responsible for an incredible array of important functions in your body including digestion, hormone balance (including conversion of thyroid hormone (T4) into the active form T3), neurotransmitter metabolism, brain function, detoxification, and keeps the delicate gut lining intact and healthy. When this microbiome becomes imbalanced or disrupted massive problems arise - including fatigue, brain fog, allergies, skin problems and many different inflammatory autoimmune conditions.

Good bacteria are known as probiotics, which are all the rage today as a supplement. Your gut really needs a healthy balance of good and bad bacteria, about 80% good to 20% bad. Your gut microbiome can become dysbiotic, or imbalanced, from many things in our 21st century lifestyle like a Standard American Diet, stress, medications, toxins, and probably the worst offender - antibiotics. Think about an anti-biotic - it is specifically designed to kill bacteria. Which bacteria? It is not specific. It kills ALL bacteria (anti = no; biotic = life). One round of antibiotics can disrupt your microbiome for life! Another common cause of dysbiosis comes from day 1 of life, a C-section birth. When a baby passes through the vaginal canal he or she receives their first and most important dosage of probiotics. If the baby misses this probiotic dosage, a slew of health symptoms can arise in a very short time. It is even suggested that during a C-section birth a mother uses a sponge to transfer the probiotics to the infant after birth!

Like the adrenal glands and stress, I have seen fantastic results by simply supporting a healthy microbiome with probiotics - for some people. At the same time (and more often than not), THIS ALONE IS OFTEN NOT THE ANSWER! Many people have had severe gut dysbiosis and leaky gut for years and need further work - cycling supplements, leaky gut support, drinking bone broth, and much, much more. Dr. David Perlmutter, a neurologist and NY Times best-selling author who specializes in the gut-brain connection, has said “the way to know if you have leaky gut is if you have a vowel in your name.” This is a joke, but the point is that in today’s society we all have intestinal permeability and gut dysbiosis and we all need to address the root cause of the problem. This is highly personal and you need to work with a physician or coach to help guide you!

7. Toxicity - Heavy Metals, Chemicals, Mold

Constant exposure to various toxins, which creates chronic toxicity, is a huge problem in today’s society. We live in a toxic, chemical soup. We have cancer-causing toxins in our kids toys, heavy metals in our food, additives in our vaccines, pollution in our air, antibiotics in our water - they are everywhere. Toxicity can cause hormone imbalance, gut dysbiosis, and can cause very severe fatigue. These toxins store in the cells of our body and affect our cellular membranes causing inflammation, including brain inflammation of the cellular membrane and the very delicate mitochondrial membrane. If you are suffering from fatigue, you have a mitochondrial problem!

Heavy metals are some of the worst toxins because of their ability to store in our cells and affect the brain neurons - mercury, lead, and aluminum being the biggest culprits. These toxins are very hard to detect, because if they are stored in our cells then they will not be present in a conventional blood, urine, or hair test. If you suspect heavy metal toxicity you absolutely have to work with a knowledgeable practitioner to determine if toxins are present and how to safely and effectively detoxify them.

Another toxin that can absolutely rob your energy is mold. There are several types of dangerous molds, not just ‘black mold’, and there is a certain percentage of the population who are genetically susceptible to mold toxicity (approximately 24% of the population carry the HLA-DR genes). Severe mold toxicity can present as something called Chronic Inflammatory Response Syndrome (CIRS). This inflammation can affect the brain and cause severe fatigue along with many other debilitating symptoms. If you suspect mold toxicity it’s incredibly important to have the right home testing, the right body testing, and the right treatment.

Dave Asprey, founder of the Bulletproof brand, has created an incredible film which is available for free at www.moldymovie.com. If you or a loved one suspect mold toxicity, I would highly recommend watching the documentary to learn more. We also have many resources for mold toxic patients on our website and Youtube channel. Mold is a HUGE PROBLEM. When we have young, otherwise healthy patients who don’t respond to quality supplements and probiotics we begin to suspect mold, and when we discuss a timeline with patients about when their symptoms begin, it’s almost creepy how much sense it begins to make that something in their ENVIRONMENT is making them sick.

8. Hidden Infections

If someone is experiencing severe fatigue and they feel like they have “tried everything” mentioned above, there is often an underlying hidden infection that is stressing their body. Some of the most common hidden infections include:

Lyme Disease (Borrelia bergdorferi) - the most common and fastest growing vector-borne infectious illness, this biotoxic disease is famous for being transmitted by ticks and presents with similar symptoms as mold toxicity - with debilitating fatigue being at the top of the list. Over 300,000 people are infected with Lyme disease each year according to the CDC, and roughly 40% of those infected will suffer long-term health problems. Like many causes of fatigue, there really isn’t a good solution in the medical model, and testing and treatment are often inadequate and leave the patient confused and with very little positive results.

Epstein-Barr Virus - the virus that causes ‘mono’, it’s estimated that 90% of people are carriers of EBV, but the infection can be ‘active’ or ‘inactive’, and infections can “re-activate” and lead to all sorts of problems. EBV is associated with Chronic Fatigue Syndrome.

Helicobacter pylori - this bacteria is also carried by many people worldwide (approximately 50%), and can be easily spread by sharing cups, silverware, etc. H. pylori can burrow into the stomach lining and causes low stomach acid, and is the most common cause of ulcers. It can also cause a myriad of other symptoms including nutrient deficiencies (especially iron and B12), small intestinal bacterial overgrowth (SIBO), gastritis, leaky gut, and chronic fatigue.

Candida - There are 17 different strains of Candida, the most common being Candida albicans. This fungal overgrowth is one of the most common bloodstream infections in the United States. Although Candida can be present in many tissues (mouth, vagina) it is especially disruptive in the gut, disrupting normal flora and causing extreme fatigue and brain fog.

These infections are incredibly hard to deal with for several reasons. For one, many people carry the infections, and in some people they cause no problems at all. Second, the infections are hard to test for and find. Third, and probably most important, the infections can hide under something called “biofilms”, which allows them to hide from conventional antibiotics.

Biofilms

Infections, especially bacterial and fungal infections, live and thrive in colonies. These colonies of bugs can produce a protective layer that they can hide under called a biofilm. This slimy layer of biofilm protects the colony and allows it to grow, move, and exist while being protected from the immune system, stomach acid, and even the most powerful antibiotics. Biofilms can contain one or more strains of bacteria, and can even contain viruses that are sharing the biofilm for protection.

In my experience, if an underlying infection is not clearing with anti-microbial/anti-fungal herbal remedies, it is important that you address the biofilms. When working with a practitioner it is important that they understand biofilms and how to dissolve them.

Conclusion

These are not the only causes of fatigue, but clinically I believe they are the Top 8 Causes that need to be considered. Fatigue is very multi-factorial, so it is crucial that you work with a coach or practitioner who understands these causes, understands the proper testing to perform, and understands how to address these causes in the right order. If you get to the root cause, you can absolutely regain your energy and get your life back!