Fatigue From Fibromyalgia Versus Chronic Fatigue Syndrome

Fatigue and low energy are very common symptoms of fibromyalgia, but like so many of the symptoms noted, this is not the same type of fatigue that a healthy person experiences. Normal fatigue in healthy individuals is a feeling of exhaustion that, after a good nights rest or even a short relaxation period, is at a manageable level if not completely gone. For people diagnosed with fibromyalgia their level of fatigue and exhaustion is total and complete. It is not corrected with simple rest and relaxation and tends to have a constant draining effect on both physical as well as mental energy.

For many people with fibromyalgia the fatigue and exhaustion is often considered just as debilitating as the chronic pain. Imagine getting up in the morning feeling exhausted, both physically and mentally, as you were when you went to bed. Every activity you do seems like you have just run a marathon, even if you have just walked to the door. Being active by doing normal activities of daily care such as getting ready for work, walking the dog, playing with the kids or even going out of the house to get groceries or spend time with friends is simply too much.

Energy levels, physical and mental, are also very low and easily depleted. Individuals with fibromyalgia want to be more active, but their bodies and brains simply don’t have the energy to stay active. This is a huge issue when working as many find that they need to take multiple naps or sit down and relax during the day, but they aren’t refreshed or re-energized by these breaks. People that don’t understand the energy drain that the chronic pain and sleep irregularities cause may be highly critical and negative towards the fibromyalgia patient, further leading to feelings of low self-esteem and depression.

Fibromyalgia And Chronic Fatigue Syndrome

Fatigue is not an uncommon symptom of many different health conditions. Other autoimmune disorders, infections, inflammations and genetic conditions can all have symptoms of fatigue. In fact, fatigue and headaches are some of the most common symptoms found in patients seeking care for any reason.

One condition that is often confused with fibromyalgia is chronic fatigue syndrome (CFS). Like fibromyalgia it is a syndrome, which means it is diagnosed by a number of symptoms being present rather than a specific medical test. Like fibromyalgia chronic fatigue syndrome is characterized by extreme fatigue, however it must be present for at least six months and typically is associated with an initial bout or prolonged health condition that is similar in nature to the flu. Like fibromyalgia it can also be associated with prolonged or intensively longer duration periods of stress.

The Centers for Disease Control and Prevention require the following two conditions to be present for a diagnosis of chronic fatigue syndrome:1

  1. Onset of unexplained, persistent fatigue that is not lifelong and is not related to increased activity, is not improved by rest and that decreases normal activity levels


  1. Four of the following symptoms that have been present for at least six months:
  • Problems with memory and concentration
  • Post-exertional malaise
  • Unrefreshing sleep
  • Muscle pain
  • Pain in multiple joints
  • Headaches that are more numerous or more severe
  • Sore throat with tender lymph nodes

Patients may also have many other symptoms including digestive disorders, night sweats, brain fog, shortness of breath and chest pains, chronic cough, eye and vision problems, allergies and food sensitivities that are new onset, dizziness and balance problems, psychological problems such as depression, panic attacks and anxiety

In some studies it has been reported that as many as 20-70% of patients diagnosed with fibromyalgia also have the required symptoms to be concurrently diagnosed with chronic fatigue syndrome. Researchers also indicate that between 35-70% of all people with chronic fatigue syndrome will also meet the diagnosis for fibromyalgia. This may indicate a similarity in pathophysiology between the two conditions that may be effective in a comprehensive treatment plan and greater understanding of both conditions. 2 Some physicians believe these two syndromes are actually different ends of the same spectrum. In essence, they may be the same disease process, but some people experience more fatigue and some experience more pain.

The Differences

The biggest differences in chronic fatigue syndrome and fibromyalgia is that CFS is largely seen as a issue concerning the inability of the body to respond to fatigue even with rest, while fibromyalgia symptoms are more connected with widespread pain in the body. Both symptoms can have pain and both can have fatigue, but it is the type, extent and significance of these individual symptoms that makes the difference in diagnosis.

Fatigue from fibromyalgia is often related to poor sleep patterns due to pain and discomfort in the spine, neck and body that prevent effective sleep. Often for patients with fibromyalgia, when effective pain management is implemented, the sleep issues will resolve themselves and provide the patient with a restful night’s sleep. Those patients with pain and chronic fatigue syndrome will not get a more restful sleep with effective pain management, although this may play a role. Instead their treatment will focus on achieving a restful sleep that allows the body to rejuvenate and repair so that energy levels are increased.

Research on heart rate variability in those with chronic fatigue syndrome may also prove valuable in obtaining a diagnosis. In research studies to test the parasympathetic system functioning in patients with CFS during sleep, it was found that these patients have different heart rate variability than the control group. The study showed the patients with chronic fatigue syndrome had lower vagal modulation of heart rate which indicated that the sympathetic nervous system, which is responsible for preparing the body for flight or flight, is highly sensitive during sleep. 3 This could be a major factor in the lack of restorative sleep noted by those with CFS compared to those with fibromyalgia who may have interrupted sleep.

One other factor often considered when determining a diagnosis is the time of onset of the condition. If the symptoms began after an injury, accident or traumatic experience of major surgical procedure, a diagnosis of fibromyalgia is more likely. In addition, the specific symptoms that are exhibited, which are largely presented as self-report by the patient, are instrumental to the physician making the determination. Fatigue itself is not the deciding factor. However, extreme fatigue occurring after muscle exertion, that does not respond to rest and lasts more than 24 hours, can be an important determinant between the two.


1 Chronic Fatigue Syndrome (CFS). (n.d.). Retrieved from Centers for Disease Control and Prevention: www.cdc.gov/cfs/general/symptoms/

2 Afari, N., & Buchwald, D. (2003). Chronic Fatigue Syndrome: A Review. The American Journal Of Psychiatry , 221-236.

3 Burton, A. R., Rahman, K., & Kadota, Y. (n.d.). Reduced heart rate variability predicts poor sleep quality in a case–control study of chronic fatigue syndrome. Experimental Brain Research , 71-78

This article was originally published on July 11, 2012 and last revision and update of it was 9/7/2015