Cause of Chronic Fatigue Syndrome

Finding the Cause of Chronic Fatigue Syndrome: Peeling Back the Layers of the Onion

Dr. Jessica Jellison, MD Author Dr. Jessica Jellison, M.D.
Functional Medicine Doctor
Chronic Fatigue Syndrome Expert

Diagnosis | Symptoms | Causes | Treatment | Lifestyle
Imagine going to the grocery store for a simple shopping trip and being exhausted for days. Or not having the energy to take a shower or make yourself a meal. For some people, no matter how much rest they get, they just can’t seem to shake the extreme fatigue they feel.

This is called chronic fatigue syndrome (CFS), also known as myalgic encephalomyelitis (ME). It is characterized by extreme tiredness and fatigue that isn’t improved by rest. For many people with CFS, this means a crushing debilitating exhaustion that prevents them from living their life as they used to, keeps them away from doing their daily activities, or even getting out of bed.

CFS is often dismissed as the “yuppie flu” because it tends to impact highly successful, driven people. Since the complexity of this condition is poorly understood by Western medicine, extreme fatigue is commonly brushed off by doctors and patients alike

But, chronic fatigue syndrome is a devastating condition that adversely affects quality of life. It is estimated that about 90 percent of people with ME/CFS have not been properly diagnosed.[1]

Increasing education and developing a better understanding about all the layers of this condition can make the difference between lifelong suffering or living a functional, productive life.

In this article, I will share the functional medicine approach to chronic fatigue syndrome, including some of the common symptoms, underlying causes and risk factors. The information in this article is meant to educate you about these various aspects and help you discuss the best treatment plan with your doctor.

Chronic Fatigue Syndrome Diagnosis: Where Do I Fit?

Chronic Fatigue Syndrome Diagnosis: Where Do I Fit?

People with CFS often feel like every system in their body is not working. The crushing fatigue can make daily tasks such as preparing food, taking a shower, or brushing hair very difficult.

To date, there are still no laboratory tests that diagnose CFS/ME directly. The diagnosis is based on an evaluation of a person’s symptoms in combination with their medical history. This leaves a lot of room for individual interpretation of symptoms by doctors. According to the Institute of medicine diagnostic criteria for CFS:[2]

  • Symptoms range for about six months, with moderate, substantial or severe symptoms for at least half of the time
  • Post-exertional malaise
  • Unrefreshing sleep

With at least one of the following:

  • Cognitive impairment
  • Orthostatic intolerance

But what exactly do these mean to you? Is your fatigue substantial enough to be considered CFS?

Unfortunately, many people with CFS end up not been diagnosed correctly. I see patients that have already gone to see psychiatrists and found themselves with a prescription for psychiatric or sleep medications. Becoming aware of some of the common symptoms and early signs of CFS is extremely important in order to avoid misdiagnosis and unnecessary suffering. Understanding this disease is like peeling back the layers of an onion, each layer must be removed to fully capture the underlying causes and contributing factors.

Common Chronic Fatigue Symptoms

Common Chronic Fatigue Symptoms

Symptoms of CFS can vary from one person to another, although some of the more common ones include:

  • Extreme tiredness, you may feel permanently exhausted, even after a good night sleep
  • Trouble sleeping or staying asleep
  • Difficulty to think or focus, “brain fog”
  • Constant headache
  • Can’t tolerate standing for a long time
  • Enlarged lymph nodes in your armpits or neck
  • Sore throat
  • Joint or muscle pain
  • GI issues such as bloating, excess gas, burping after meal, diarrhea or constipation

Know the early warning signs & timeline

Symptoms of chronic fatigue do not occur overnight, and usually evolve over time. Very often, in the earlier stages, in addition to the fatigue, there are other symptoms that may seem completely unrelated, such as occasional joint pain, “brain fog”, or GI issues. As a result, these are ignored or treated individually.

In functional medicine, when we sit down to create a timeline based on a patient’s medical history we can begin to track down the progression of the disease and its contributing factors. We can put each layer together to see a complete picture.

If you are experiencing unrelenting fatigue, it is important to be mindful to any symptoms you have and share them with your doctor. Some of these signs often become worse or more apparent after stressful life events.

Potential Contributing Causes

In functional medicine, we approach the body as a whole, rather than concentrating on just one area. Just like peeling back the layers of an onion, we investigate each patient’s unique situation to reveal the unique root causes behind their illness.

There are several risk factors and underlying health conditions that can contribute to the development of CFS. The entire picture needs to be evaluated by a trained clinician to determine the right diagnosis. Each individual underlying cause may completely change the necessary tests required and the treatment. Below are some of the more common ones:

Underlying Infections

  • Epstein–Barr virus (EBV)
  • Tick borne illness, Lyme disease
  • Yeast infection

Mold Exposure

Common Chronic Fatigue Causes - Mold

A growing amount of evidence suggests there is a strong link between chronic fatigue and mold exposure.

Just to share with you some of the literature, a study conducted in 2013, found that out of 112 CFS patients, 93% had the presence of mycotoxins (mold toxins) in their urine.[3]

Exposure to mold in water damaged buildings can be a serious risk factor to look for if you are struggling with fatigue. Genetics in this case, may also play a key role. Approximately 24% of the population is genetically susceptible to mycotoxins. As a result, their immune system may not able to effectively eliminate mold biotoxins.

Additional Lifestyle Risk Factors

  • Diet: the standard American diet is high in processed foods, sugar, and toxins, yet low in many critical nutrients. It has been linked to many health conditions and may play a significant role in CFS.
  • Sleep disruptions: may compromise quality of sleep leading to fatigue. When relevant, your doctor may decide to conduct a sleep study.
  • Heavy metal toxicity, exposure to environment pollutants through occupation or diet.

Additional Contributing Factors

  • Hormonal imbalances
  • High cholesterol
  • Sugar issues and prediabetes.
  • Inflammation: Erythrocyte sedimentation rate, also known as ESR detects inflammation in the body. While this test can’t determine if a patient has CFS, patients with CFS usually have very low score, which can help the diagnostic process.
  • Medication

Treatment Approach for CFS

Treatment plan for CFS should always be tailored to the individual’s risk factors, needs, and concerns. With that said, there are a few fundamentals that can play a key role and should always be considered:


Chronic Fatigue Syndrome Diet Foods to Eat and Avoid

With the extreme fatigue that often comes with CFS, the last thing you may have in mind is your diet, going to the grocery store, or worrying about what to cook for dinner. Diet however is extremely important in the development and treatment of the disease. The good news is that even taking baby steps may help you feel better.


  • Processed foods
  • Sugary drinks and high carb foods such as bread and cereals. These foods can cause high spikes in your blood sugar levels making you feel worse.

Eat: Perimeter Shopping

  • Focus on fresh fruits, vegetables and leafy greens.
  • Choose grass fed animal proteins.
  • Drink enough water. Choose filtered water. Aim to drink half your body weight in ounces.
  • Minimize pesticides, hormones, antibiotics and toxins. Try to eat organic as much as possible.

Supplements: Nourishment, not Stimulants

Chronic Fatigue Syndrome Supplements

Part of the diagnosis of CFS should be assessing any underlying nutritional deficiencies that are contributing to the fatigue. Optimizing nutritional status is also a very important part of the healing process. I highly recommend working with your doctor and having your nutrient levels tested, so you can address any deficiencies with the right dietary changes and supplements.

Dietary supplements should be specific to each patient and greatly depends on the underlying cause of CFS. With that said, some of the more common supplements used to improve fatigue may include:

  • Common nutritional deficiencies such as B12, vitamin D, and iron
  • Mitochondrial support with: CoQ10, Acetyl-L-carnitine, D-ribose, B-complex

Notice that these supplements support energy production in the body. These are different from stimulants and other “energy supplements” that may boost your energy for a few hours, but can backfire when used long term.

Living with Chronic Fatigue Syndrome

Living with Chronic Fatigue Syndrome

With CFS, you may feel overwhelmed and choose to avoid physical activity or even social interaction. Staying at home all day, however, may worsen your symptoms. Certain lifestyle choices, even minor ones, can improve the way you feel, both physically and mentally.

Here are a few healthy lifestyle suggestions for you to consider. Try to take small baby steps, one at a time, and see how you feel.

  • Movement & Exercise. When you are exhausted last thing you want to do is be more active, but even five minutes of gentle activity such as walking in nature or stretching can help you feel better.
    Always look for an activity that matches your fitness level. Doing high intensity exercise when you have CFS can backfire.
  • Spend time in nature. Spending time in nature can calm your nervous system and promote a sense of well-being. Taking your dog for a walk or the kids to the park for ten minutes may be all it takes to make you feel better.
  • Manage Stress. Feeling tired all the time often creates more stress and leads to low mood. Meditation apps that have simple breathing exercises offer a gentle, yet effective way to manage stress.
  • Social. We are all social beings. Try to spend more time with your friends, family, or get involved more in your community.

Final Thoughts

Being diagnosed with chronic fatigue syndrome can be overwhelming. We now have enough data, to peel back the layers of the onion and address the underlying causes, so you can live a much more functional productive life.

I hope you find this total-wellness approach to chronic fatigue syndrome helpful. I wish you the very best success in your journey to a better health.

Dr. Jessica Jellison, MD

1 thought on “Finding the Cause of Chronic Fatigue Syndrome: Peeling Back the Layers of the Onion”

  1. 5 stars
    In this article, Dr. Jessica Jellison, M.D. will share the functional medicine approach to chronic fatigue syndrome, including some of the common symptoms, underlying causes and risk factors. The information in this article is meant to educate you about these various aspects and help you discuss the best treatment plan with your doctor.

Leave a Comment