What should I know about fatigue?

Lethargy, weariness, lassitude. These are terms that are commonly used to describe a lack of energy. It’s normal to feel run down and in need of a nap every once and awhile. Some people however, feel this way on a regular basis. Doctors often refer to recurring feelings of low energy as fatigue.

Fatigue can be related to underlying medical conditions, poor nutrition and stress, as well as other factors. While it can often be difficult to discern the root cause of fatigue, it is commonly a symptom of disorders such as fibromyalgia, chronic fatigue syndrome, and hormonal disorders such as Addison’s disease and hypothyroidism. Some specific forms of fatigue involving loss of muscle strength may be associated with kidney, liver, heart, and lung disease. Often however, it can be difficult to distinguish fatigue that is a result of these disorders and fatigue that arises from a simple lack of sleep. This may be particularly true when an underlying disorder results in chronic sleep disruption or in abnormal sleep.


The Psychiatry Research Trust, 2007.

  • 20-50% of the population report suffering from fatigue.

Signs and Symptoms

[span class=alert]The following list does not insure the presence of this health condition. Please see the text and your healthcare professional for more information.[/span]

Fatigue is itself a symptom and should be checked by a physician for an underlying cause. Fatigue can result from various diseases involving the heart, kidneys, liver, and lungs. Multiple sclerosis patients suffer from fatigue, as well as those suffering from various types of cancer. There are numerous diseases for which fatigue is a symptom and it may present in several different manners. The most common are complaints of weakness or loss of muscle strength (asthenia), weariness, lassitude, low energy, and mental fatigue.

Treatment Options


Because fatigue is often a symptom of an underlying disorder, it is important for people who feel they may be suffering from fatigue to receive a proper diagnosis of from a health care professional. After diagnosis, and if other factors that may be causing fatigue are ruled out, doctors sometimes recommend good old-fashioned caffeine. Caffeine is the only FDA-approved stimulant ingredient for treating fatigue and drowsiness. As most people know, it occurs naturally in some foods and beverages and is added to others.

Nutritional Suplementation


Iron deficiency anemia is known to cause symptoms such as fatigue and weakness, especially in pregnant women. In fact, fatigue and low energy are common occurrences in women before, during, and after pregnancy. (1) Iron deficiency occurs more frequently in women, and fatigue is one of the primary symptoms associated with this condition. (2) However, postmenopausal females and adult males, unless they are diagnosed with iron deficiency anemia, should not take iron supplements. Iron intake has been associated with increased risk for cardiovascular disease in these patients.


Fatigue is one of the many symptoms that can be caused by magnesium deficiency. Magnesium is crucial to a number of chemical interactions in the body that metabolize nutrients and produce energy. More specifically, magnesium may play a role in the efficiency of the cellular mitochondria, the so-called "powerhouse" of the cell. (3) A number of studies suggest that magnesium may be instrumental in other aspects of energy production at the cellular level. (4) The role of magnesium in energy production and endurance was also examined among twenty-three competitive triathletes. Researchers found that swimming, cycling, and running times improved in those athletes taking a magnesium supplement. (5)


Like magnesium, this nutrient may also play a role in the production of energy in the body. Carnitine is instrumental in the conversion of certain types of fatty acids into fuel for the mitochondria. Production of energy in the mitochondria from these fatty acids is especially important in heart and skeletal muscles. For this reason, L-carnitine may be of benefit to those who suffer from chronic fatigue syndrome. (6) The findings of one study suggest that carnitine supplementation may help improve mitochondrial energy production in patients with the disorder. (7)

Vitamin B12

A deficiency in this nutrient develops slowly over time. Some of the most common early symptoms of a deficiency include fatigue, generalized weakness, and depression. Causes of vitamin B12 deficiency include anemia, syndromes that cause poor absorption of nutrients, drug-induced vitamin depletion, strict vegetarianism, and tapeworm infection.

Folic Acid

A deficiency in this nutrient is often found in patients with chronic fatigue syndrome. According to research, in some cases, patients with folic acid deficiency can develop muscular and intellectual fatigue along with depression and a variety of other symptoms. Studies suggest that folic acid therapy can help these patients recover. (8) , (9)

Vitamin B6

There is some evidence to suggest that pyridoxine deficiency may be linked to chronic fatigue syndrome. (10)

Nicotinamide Adenine Dinucleotide (NADH)

Also known as coenzyme I, NADH is present in all living cells and plays a critical role in the production of cellular energy in the mitochondria. The more NADH cells have available, the more energy the mitochondria can produce. Studies suggest that NADH supplementation can indeed support more efficient energy manufacture at the cellular level. (11) Another study suggests that NADH may be a valuable therapy in the management of the chronic fatigue syndrome and possibly in patients suffering from other forms of fatigue. (12)

Dehydroepiandrosterone (DHEA)

Much study has focused on the anti-aging potential of this hormone, which is a precursor for many of the steroid hormones produced in the body. (13) As the body ages, however, levels of DHEA decrease and studies suggest that supplementing with DHEA may increase perceived physical and psychological well-being. It may also provide increased energy, deeper sleep, a sense of greater relaxation, and better moods. (14)

Another study looked at DHEA’s possible role in treating chronic mild depression, a condition which is often linked to fatigue. After supplementation, test subjects reported increased energy and feelings of emotional well-being. (15)

Omega-3, Omega-6

These essential fatty acids (EFAs) are required for an enormous number of biological and physiological processes. Studies suggest that supplementation with EFAs may also play a role in alleviating post-viral fatigue syndrome. (16) Symptoms of the disorder such as fatigue, myalgia, dizziness, poor concentration, and depression may be eased by EFAs.

Coenzyme Q10 (CO-Q10)

This nutrient is required for the production of energy in the mitochondria of all cells. Therefore, coenzyme Q10 supplementation may improve aerobic capacity, energy production, and muscle performance, especially in individuals who suffer from a deficiency of the nutrient. In one study of coenzyme Q10, sedentary men who were administered coenzyme for 4 to 8 weeks showed increases in oxygen consumption and work capacity. (17)

Congestive heart disease is an extreme example of low energy and fatigue. Coenzyme Q10 helps improve energy production in the heart, which is why CoQ10 has been called a scientific breakthrough in the treatment congestive heart failure. Because of its key role in the production of cellular energy, coenzyme Q10 is one of the primary nutrients that are recommended in the treatment of other fatigue-related conditions. (18)

Herbal Suplementation


Cordyceps is a unique black mushroom that extracts nutrients from and grows only on a caterpillar found in the high altitudes of Tibet and China. Even though it is difficult to find and harvest, cordyceps is one of the most valued medicinal agents in the Chinese medical tradition.

Fortunately for consumers, a patented lab fermentation process has allowed large-scale production and availability of cordyceps. While it has served for centuries as a general tonic for promoting longevity, vitality, and endurance, it is now being researched for its potential for increasing energy, among other benefits. Cordyceps ability to increase vitality and respiratory health is linked, studies suggest, to its role in improving the availability of oxygen to the lungs and bloodstream. (19)


Use of the schisandra berry dates back centuries when Chinese medical practitioners found it useful for support of the kidneys and as a sedative. In Russia, schisandra has been used to increase the body’s natural ability to fight off disease and stresses from chemical, physical, mental, and environmental sources.

Schisandra has historically been used to treat cough and wheezing, spontaneous sweating, chronic diarrhea, insomnia, and forgetfulness. However, Schisandra has also been reported to increase human endurance and mental and physical performance. Other historical uses include use to improve mental efficiency and sensitivity of sight, hearing, and touch.


Rhodiola has been used in traditional folk medicine in China, Serbia, and The Ukraine. In the former Soviet Union, it has been used to decrease fatigue and increase the body’s natural resistance to various stresses. In Siberia, it is said that, "those who drink rhodiola tea regularly will live more than 100 years."

Some modern experts think rhodiola may indeed be able to enhance health in a wide variety of ways. More specifically, it may strengthen the nervous system, fight depression, enhance immunity, elevate the capacity for exercise, enhance memorization, and improve energy levels. In keeping with Siberian folklore, some experts add that rhodiola may even prolong the life span.

There are some studies that have attempted to validate the numerous claims made about this supplement. One such study in rats suggests that rhodiola may indeed enhance learning capacity and memory. (20)

Meanwhile, informal studies have suggested that rhodiola may enhance athletic performance by improving the ratio of muscle to fat in the body. Other suggest that rhidiola may also enhance our moods and fight depression by stimulating the activity of neurotransmitters that are crucial to mental well-being. (21) Russian scientists have used rhodiola, often in combination with conventional antidepressants, to decrease the symptoms of seasonal affective disorder (SAD) common to Northern European countries.

Panax Ginseng (Asian)

With products containing ginseng available at many corner markets, it’s hard not to have heard about it. In fact, ginseng is the most frequently purchased herbal supplement in the United States. Historically, it has been used for a variety of health benefits, especially for its ability to help the body cope with stress and fatigue.

Research suggests that Asian ginseng may be involved in a complex interaction of hormonal pathways that regulate the body’s response to stress. (22) , (23) Asian ginseng has been recommended for use by people who are athletes, fatigued, or have high stress jobs.


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