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7 Causes Of Chronic Fatigue That Are Often Overlooked: A Doctor Explains

Evan Hirsch, M.D.
December 6, 2016
Evan Hirsch, M.D.
Family Medicine Doctor
By Evan Hirsch, M.D.
Family Medicine Doctor
Evan Hirsch, M.D., is a family medicine doctor who specializes in healing chronic fatigue. He is Board Certified in Family Medicine and Integrative Medicine.
Photo by Stocksy
December 6, 2016

Chronic fatigue—a condition defined as persistent fatigue that cannot be alleviated by rest—affects1 nearly 2.5 million Americans. For those folks, waning energy levels and low vitality can make every day a struggle.

As a medical doctor who specializes in fatigue, I see it manifest in a variety of ways. I also know that some interventions work for certain patients but not for others, and this can make treatments difficult. When they first visit my office, many patients have seen numerous practitioners (without any success) and many are convinced that they must simply learn to live with their fatigue.

You do not have to live with fatigue.

After working with thousands of patients, I can confidently say that you do NOT have to live with fatigue and the misery it can bring. And while fatigue can have many different causes and seem overwhelming, my treatment approach systematically identifies any potential factors driving fatigue and then eliminates them—for good.

Here's how to identify the cause of your fatigue.

Fatigue has many roots and the first step in treatment is to rule out out any obvious causes like diabetes and cardiovascular disease. Next I check for poor sleep, chronic stress, nutrient deficiencies, food intolerances and allergies, and insufficient exercise, all of which are2 more obvious fatigue triggers. Finally, I look for the less obvious culprits that—in the complicated web of symptoms and causes—can be easy to overlook. In my experience, I find that these seven culprits often trigger or exacerbate fatigue in many of my patients:


Your adrenals sit on top of your kidneys and produce the stress hormone cortisol. Chronic stress causes3 an initial increase in cortisol but then levels start to decline and this oftentimes manifests as burnout and fatigue.


Thyroid dysfunction is a major cause of fatigue, yet many conventional practitioners tell patients their thyroid function is fine because labs produce “normal” numbers. Unfortunately, those numbers4 don’t tell the whole story.

Sex hormones

Deficiencies or imbalances in progesterone, estrogen, and testosterone in men and women often contribute5 to chronic, unexplainable fatigue.

Heavy metals and chemicals

Toxins bombard air, soil, food and water and can overwhelm your detoxification systems. Lead, aluminum, formaldehyde, plastics, pesticides, drugs, mercury in fish and amalgam fillings are some of the most common6 fatigue-sparking toxins.


Infections from bacteria, parasites, viruses, fungi, and other microorganisms can create7 fatigue. Frequent culprits include the Epstein-Barr Virus, Lyme disease, yeast, mold, Multiple Antibiotic Resistant Coagulase Negative Staphylococci (bacteria in the nasal cavity), and Small Intestinal Bacteria Overgrowth (SIBO).


Mold is sneaky, toxic, and a huge problem8 in my patients’ home and workspaces. If your environment contains mold, you can’t eliminate fatigue until you get rid of it.


Every cell has these little “power plants” that produce energy. Heavy metals, chemicals, molds, and infections can reduce9 mitochondrial production and function.

Once you are able to target the causes of your specific fatigue, you can devise an in-depth strategy to minimize their negative impact. This will restore steady, sustained energy levels so that fatigue can stop holding your life, your health and your happiness hostage.