What Is Fibro Fog and ME/CFS Brain Fog?

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


While we don't know exactly what's behind our cognitive problems, researchers are learning more about them all the time.

One study suggested that people with both FMS and ME/CFS had more cognitive impairment than those with ME/CFS alone. The ability to remember what is heard appeared to be worse in those with higher pain. Problems with visual perception, meanwhile, were linked to severe cases of ME/CFS without overlapping FMS.

Another study on these conditions together found a link between the brain's ability to tune out pain (pain inhibition) and its ability to tune out other extraneous stimuli (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. Researchers also noted that higher self-reported pain appeared linked to slower reaction times in ME/CFS-only.

One research team 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 that cognitive impairment appeared to be linked to:

  • Sensitization
  • Impaired pain processing 
  • Hyperalgesia (amplified pain) 
  • Lower health-related quality of life

Many people with these conditions complain that they have trouble coming up with words. One study showed that people with FMS were slower at word recall than other people with memory deficits and also had deficits in more areas of cognitive measurement.

Remembering what we hear is also difficult for many with these conditions and at least one study backs this up. Researchers found impairment in how auditory information is processed in the brains of people with FMS. New research is published regularly. As we learn more, we may gain treatments aimed specifically at our cognitive dysfunction.


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:

In FMS, fibro fog generally is worse when pain is worse. In both FMS and ME/CFS, it can be exacerbated when you're especially fatigued, anxious, under pressure, 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 in these conditions is not related to symptoms of depression.

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

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.


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 can include:

  • Word use and recall: Difficulty recalling known words, use of incorrect words, slow recall of names for people and items
  • Short-term ("working") memory problems: Forgetfulness, inability to remember what's read or heard, forgetting what you were doing, losing train of thought
  • Directional disorientation: Suddenly not recognizing familiar surroundings, easily becoming lost, having trouble remembering how to get somewhere
  • Multitasking difficulties: Inability to pay attention to more than one thing, forgetfulness of original task when distracted
  • Confusion and trouble concentrating: Difficulty with processing information, being easily distracted, trouble learning new information
  • Math/number difficulties: Difficulty performing simple math, remembering sequences, transposing numbers, trouble remembering numbers and dates

Some people may also have other types of cognitive dysfunction, too.


For some people, brain fog resolves with effective treatment for pain or sleep problems. However, not everyone can find effective treatments, which leaves many of us trying to manage this symptom.

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 and vegetables
  • Carbohydrates

Some FMS research shows that moderate exercise can help improve cognitive function as well. Exercise is difficult for us, so be sure you know the right way to get 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 even 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, as well.

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.

A Word From Verywell

Cognitive dysfunction is tough to live with. It can be frustrating, embarrassing, and difficult to overcome. But, by working with your doctor to find the right mix of treatments and finding ways to keep your brain active and compensate for your cognitive losses, you may be able to mitigate the damage this symptom has done to your life.


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