Brain Fog / Fibro Fog in Fibromyalgia & Chronic Fatigue Syndrome

What Causes It & What to Do About It


Brain fog (also called fibro fog or cognitive dysfunction) is one of the most common complaints of people with fibromyalgia (FMS) and chronic fatigue syndrome (CFS or ME/CFS). For many, it can be severe and can have just as big an impact on their lives as pain or fatigue. In fact, some people say brain fog is more of a disability than their physical symptoms.

What Causes Brain Fog?

We don't yet know exactly what causes cognitive dysfunction in these conditions, but we have a lot of theories about possible contributing factors, including:

  • Lack of restorative sleep
  • Abnormal cranial blood flow or volume
  • Brain abnormalities
  • Premature brain aging
  • Mental distraction due to pain

In FMS, brain fog generally is worse when pain is worse. In both FMS and ME/CFS, it can be exacerbated when you're anxious, rushed, or dealing with sensory overload.

Depression, which is common in FMS and ME/CFS, also is associated with cognitive dysfunction. Some studies, however, show that the severity of brain fog is not correlated with depression symptoms.

A lot of common medications for FMS and ME/CFS can contribute to brain fog as well.


Symptoms of brain fog can range from mild to severe. They frequently vary from day to day, and not everyone has all of them. Symptoms include:

  • Word use & recall: Difficulty recalling known words, use of incorrect words, slow recall of names.
  • Short-term memory problems: Forgetfulness, inability to remember what's read or heard.
  • Directional disorientation: Not recognizing familiar surroundings, easily becoming lost, having trouble recalling where things are.
  • Multitasking difficulties: Inability to pay attention to more than one thing, forgetfulness of original task when distracted.
  • Confusion & trouble concentrating Trouble processing information, easily distracted.
  • Math/number difficulties: Difficulty performing simple math, remembering sequences, transposing numbers, trouble remembering numbers.

Some people may also have other types of cognitive dysfunction.

The Research

Researchers are learning more about our cognitive problems all the time.

A 2015 study (Schmaling) suggested that people with both FMS and ME/CFS had more cognitive impairment than those with ME/CFS alone. Verbal memory appeared linked to pain. Problems with visual perception, meanwhile, was linked to those with severe cases of ME/CFS and without FMS.

Another 2015 study (Ickmans) on these conditions together found a link between the brain's ability to tune out pain (called pain inhibition) and its ability to tune out other extraneous stimuli (called cognitive inhibition.) Pain inhibition is a known feature of FMS. Poor cognitive inhibition could mean, for example, that you can't follow a conversation while the TV is on because your brain can't filter out the background noise.

In the same study, researchers also noted that higher self-reported pain appeared linked to slower reaction times in ME/CFS-only.

One research team (Coppieters) explored the connection between cognitive ability and central sensitization -- an overly sensitive central nervous system -- which is believed to be a key underlying feature of FMS, ME/CFS and other related conditions.

They found:

  • Cognitive impairment appeared linked to sensitization;
  • Cognitive performance appeared significantly related to impaired pain processing, hyperalgesia, and lower health-related quality of life.

Many people with these conditions complain that they have trouble coming up with words. A 2014 study (Leavitt) showed that people with FMS were slower at coming up with words than other people with memory deficits. Those in the FMS group who showed word-finding problems also had deficits in 10 out of 12 cognitive measurements, while those with word-finding problems in the memory-deficit group only showed deficits in 8.

Remembering what we hear is also difficult for many with these conditions, and at least one study (Choi) backs this up. Researchers found impairment in how auditory information is processed in the brains of people with FMS.

This is just a sampling of research on brain fog, and more is published regularly. As we learn more, we may gain treatments aimed specifically at our cognitive dysfunction.

Learning Disorders

So far, we don't have evidence that our brain fog comes from known learning disorders. However, our problems are similar to those associated with disorders such as dyslexia (reading problems), dysphasia (speaking problems) and dyscalculia (math/time/spatial problems).

If you believe you could have a recognized learning disorder, talk to your doctor. A diagnosis could help you get reasonable accommodation at work or strengthen a disability benefits claim. Proper treatment could help you function better, as well.

Lifting the Fog

For some people, brain fog resolves with effective treatment for pain or sleep problems. (See Treating Fibromyalgia and Treating Chronic Fatigue Syndrome for information on treatment options.)

However, not everyone can find effective treatments, which leaves many of us trying to manage brain fog.

Supplements are a common choice. While we don't have a lot of evidence to support their effectiveness, some doctors and people with these conditions say they've seen supplements help with cognitive function. Common brain-fog supplements include:

Some doctors recommend dietary changes to include "brain friendly" foods, some of which are natural sources of the supplements listed above. Some of these foods are:

  • Fish (Omega-3)
  • Canola or walnut oil (Omega-3)
  • Eggs (Choline)
  • Fruits & vegetables
  • Carbohydrates

Some FMS research shows that moderate exercise can help improve cognitive function as well. Exercise is difficult for us, so be sure to read Getting Started With Exercise.

Cognitive Training

Researchers are learning more about the brain and how it works, and new information could help us understand brain fog. Research on aging brains and some degenerative brain conditions shows that cognitive training can slow, stop or sometimes reverse cognitive dysfunction.

Some doctors use cognitive training programs, which often include software that you use at home. Video game companies and websites offer games they claim can improve cognitive function, and while specific games haven't been evaluated for this ability, some evidence does suggest that virtual reality games improve memory and critical thinking skills.

Because this is an emerging area of science, we're likely to learn more about cognition and cognitive training in the years ahead.


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