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Brain Fog

Updated: Apr 4, 2022

Brain fog has caught public attention recently because it was found to be one of the aftermaths of COVID-19 infection. However, brain fog is not specific to COVID. It has been experienced in people who suffer from other physical and mental conditions as well, such as lupus, chronic fatigue syndrome, hypothyroidism, stroke, traumatic brain injury, dementias, autoimmune diseases, inflammatory diseases, vestibular dysfunction, depression, anxiety, chronic insomnia, etc. Some people also report brain fog after surgical operations and/or chemotherapy.

Brain fog is a lay term referring to general mild cognitive difficulties. The experience of people with brain fog varies. People usually describe themselves living in a fog, where connections to the outside world is muddled and blocked. The common mild cognitive difficulties related to brain fog are clouding of consciousness, mental confusion, poor concentration, mental slowness, word finding problems, memory difficulties and disorganization. People also report extreme and chronic fatigue, and the sense of being easily overwhelmed by mental demands and environmental stimulations. When they try to concentrate and work hard on a piece of work, some of them report headaches and/or dizziness as well.

The etiology of brain fog is not yet clearly understood. One of the hypotheses maintains that chronic neuroinflammation resulted from damage of the blood-brain barrier is involved (Kverno, 2021). The blood-brain barrier is a mechanism that normally block harmful materials, including viruses and bacterias, from entering into the brain in order to protect the neurons. However, under certain circumstances, such as chronic inflammation, the over-activation and prolonged expression of the immune system may damage the barrier mechanism. It would result in neuroinflammation and multisystem inflammatory syndromes, where chronic activation of proteins associated with immunity leads to an attack or phagocytosis of normal brain cells.

Brain fog is not directly measured by psychometric tests in neuropsychological assessment. Instead, the testing helps to delineate the characteristics of the brain fog experienced by a particular individual. It taps on how the cognitive performance is compromised in terms of attention and concentration, working memory, cognitive speed, memory, language and executive functions.

There is no known empirically validated treatment for brain fog yet. It follows the neuroinflammatory hypothesis that the management could involve the treatment of the inflammation in the brain through pharmacological intervention. Non-pharmacological attempts to manage brain fog include cognitively stimulating activities, physical exercises, improved sleep pattern, light therapy, structured daily activities, psychotherapy, etc. People with brain fog could consult your medical doctors for pharmacological interventions, and your neuropsychologists for non-pharmacological therapies.


Kverno, K. (2021). Brain fog: a bit of clarity regarding etiology, prognosis, and treatment. Journal of Psychosocial Nursing and Mental Health Services, 59(11), 9-13.

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