Fibro Fog and ME/CFS Brain Fog Overview

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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 causes our foggy brains, 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 just ME/CFS. People with more pain had a harder time remembering what they heard. This finding is backed up by at least one other study However, people with only ME/CFS appeared to have more problems with visual perception.

Another study 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 things in your environment (cognitive inhibition). Impaired 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. The link could mean that our impaired pain inhibition causes or is related to cognitive inhibition.

In the same study, researchers noted that higher self-reported pain in ME/CFS appeared linked to slower reaction times, which is a common complaint among people with this condition.

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 that they also had deficits in more areas of cognitive measurement.

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:

  • Sleep that isn't restful or restorative
  • Abnormal blood flow to some areas of the brain
  • Abnormal connectivity patterns between different regions of the brain
  • Abnormal function of certain brain chemicals (neurotransmitters)
  • Premature aging of the brain
  • Mental distraction due to pain
  • Overexertion in ME/CFS as a consequence of post-exertional malaise

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 the train of thought
  • Directional disorientation: Suddenly not recognizing familiar surroundings, easily becoming lost, having trouble remembering how to get somewhere
  • Confusion and trouble concentrating: Difficulty with processing information, being easily distracted, trouble learning new information
  • Math/number difficulties: Difficulty performing simple math or 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 for those, 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:

  • 5-HTP
  • B vitamins
  • Carnitine
  • Choline
  • Omega-3 (fish oil)
  • Rhodiola rosea
  • St. John's wort
  • SAM-e
  • Theanine

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 always 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 that may 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 symptom, 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 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. However, by working with your doctor to find the right mix of treatments, and by finding ways to keep your brain active and compensate for your brain fog, you may be able to undo some of the damage this symptom has done to your life.

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