General Fatigue And Fibromyalgia

There are several different conditions that cause extreme fatigue without a specific trigger or medical issue that can be currently identified. These conditions may all eventually be found to be linked, as suggested by many researchers, and may be due to polygenic factors where multiple genes and environmental triggers contribute to the development of the condition. Two of the most commonly known fatigue related conditions are fibromyalgia and chronic fatigue syndrome.

Both syndromes have a variety of overlapping symptoms which has made diagnosis between the two challenging. A key symptom in both conditions is the feeling of overwhelming general fatigue that occurs for unspecific reasons. This is not the same as feeling exhausted after a challenging day at the office, after staying up all night looking after a sick child or after increasing your physical activity levels. It is also not the same type of general fatigue that is noted when you are under a lot of mental or emotional stress. Fatigue associated with these types of activities is short term and, with a good night’s rest, is corrected. For people with fibromyalgia and chronic fatigue syndrome, the fatigue is ongoing and highly debilitating.

It is essential to keep in mind that while chronic fatigue syndrome and fibromyalgia both have the symptom of fatigue, in fibromyalgia there is also the high level of overall body pain combined with tender points on the body which are the predominant diagnostic symptom. With chronic fatigue syndrome there is some pain, typically around the joints, but the overlying symptom is that of fatigue.

General Fatigue Experienced

Individuals with fibromyalgia report that the feelings of fatigue they experience are very similar in nature to having the worst flu combined with complete and utter exhaustion. There is just no restoration of energy levels no matter how much you try to rest, sleep or relax. The pain is one cause of the lack of a restful sleep, but sleep is also disrupted at a more functional level since long periods of the deep sleep needed for rejuvenation at a cellular level simply does not occur.

Along with the inability to get a restful sleep, the general fatigue from fibromyalgia also results in changes in the chemistry of the brain. There is a greater chance of psychological issues such as depression, anxiety, and mood disorders. In a study of patients with depression over 80% report sleepiness and insomnia as major symptoms. In research studies these patients had different arousal functions that worked differently in the day and the night than patients not showing signs of depression. Controlling the circadian rhythms using pharmacology therapies were seen as possible options for treatment to reverse the neural changes noted in depressed patients. 1

As depression and fibromyalgia are often concurrent conditions, the importance of the brain changes in altered sleep patterns is an important research consideration. However, many patients with fibromyalgia taking the medications that are effective for patients with fatigue, sleep problems and depression do not find them as beneficial. To make this more complicated, research that followed 75 fibromyalgia patients, while tracking sleep through self-report and through actual measurement with an actigraphic device, estimated that patients tended to underestimate approximately 50% of the time the amount of sleep they actually had each evening. Researchers noted that the level of pain and fatigue they experienced in the mornings when self-reporting impacted their estimates of how long they were asleep. 2

This information leads to further interest as to why the sleep is not restorative and how much the individual’s perception of sleep, based on pain and fatigue experienced, actually impacts mental and physical health.

Fibro Fog

The constant levels of physical fatigue are debilitating in many ways. Individuals cannot participate in activities they enjoy and are often simply too physically drained to get the exercise that is seen as essential in managing the symptoms of fibromyalgia. While this is definitely problematic, many fibromyalgia patients report another kind of general fatigue that is even more devastating. This is a type of mental fatigue or extreme exhaustion that is known as fibro fog.

Fibro fog is a very general term that is used to describe the decrease in cognitive functioning in patients with fibromyalgia. This includes a wide range of changes in mental alertness and processing which can range from short term memory loss to an inability to comprehend and recall newly learned information. Other typical symptoms include problems in remembering words and their meanings, difficulty in understanding and responding to casual or informative conversations, problems in information recall in areas of prior competency, difficulty in remembering plans, lists, schedules, activities and special events.

Usually fibro fog is not constant but rather comes and goes. Typically fibro fog is most problematic during times of high levels of pain and sleep abnormalities, as well as when there are physical or mental stressors. It is important to realize that the cognitive dysfunction does not cause permanent functional disabilities to the cognitive processes. New research tends to lean towards chemical changes in the brain that limits serotonin levels, leading to problems with memory recall and learning. Changes in blood flow to the various areas of the brain may also be a cause of the temporary changes in cognitive ability.

In research studies of fibro fog, similar results to the sleep study were found. Researchers determined that those with fibromyalgia tended to score themselves higher on cognitive dysfunction on days when they had greater pain and less sleep. When individuals reported poor sleep they self-reported poorer memory recall, and when pain was a major symptom the language deficit was self-reported as worse. Fatigue and mood played the largest role in perceived dyscognition in fibromyalgia patients throughout the study.3

Finding treatments that help patients with fibromyalgia maintain healthy cognitive functioning, get a restful sleep and avoid the extreme fatigue associated with the syndrome need to be comprehensive. Often treating just one symptom with medication results in compounding the mental or physical fatigue that can lead to increased social withdrawal, depression and lack of healthy exercise for individuals with fibromyalgia.


1 Nakajima, T. (2007). Depression and sleep. Japanese Journal of Clinical Medicine, 1702-1705.

2 Okifuji, A., & Hare, B. (2011). Nightly Analyses of Subjective and Objective (Actigraphy) Measures of Sleep in Fibromyalgia Syndrome: What Accounts for the Discrepancy? The Clinical Journal of Pain, 289-296.

3 Williams, D. A., Clauw, D. J., & Glass, J. M. (2011). Perceived Cognitive Dysfunction in Fibromyalgia Syndrome. Journal of Musculoskeletal Pain , 66-75.

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