brain fog
noun
: a usually temporary state of diminished mental capacity marked by inability to concentrate or to think or reason clearly
Examples of brain fog in a Sentence
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What looks like a mindset issue (brain fog, emotional reactivity, impulsivity) is often a mitochondrial issue in disguise.
—
Ximena Araya-Fischel, Forbes.com, 14 June 2025
In addition to headaches, patients may experience ringing in the ears, vision disturbances, memory problems, brain fog, dizziness and nausea.
—Danielle Wilhour, The Conversation, 28 May 2025
There’s also emerging evidence creatine can help with medical conditions that cause fatigue, brain fog, and similar symptoms, including long COVID and chronic fatigue syndrome.
—Cindy Kuzma, SELF, 28 May 2025
My on/off symptoms of perimenopause have largely manifested as sleep deprivation, brain fog, and lack of focus and concentration.
—Devinder Bains, Glamour, 16 May 2025
See All Example Sentences for brain fog
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Ximena Araya-Fischel, Forbes.com, 14 June 2025
In addition to headaches, patients may experience ringing in the ears, vision disturbances, memory problems, brain fog, dizziness and nausea.
—Danielle Wilhour, The Conversation, 28 May 2025
There’s also emerging evidence creatine can help with medical conditions that cause fatigue, brain fog, and similar symptoms, including long COVID and chronic fatigue syndrome.
—Cindy Kuzma, SELF, 28 May 2025
My on/off symptoms of perimenopause have largely manifested as sleep deprivation, brain fog, and lack of focus and concentration.
—Devinder Bains, Glamour, 16 May 2025
See All Example Sentences for brain fog
Cite this Entry
“Brain fog.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/brain%20fog. Accessed 1 Jul. 2025.
Copy CitationMedical Definition
brain fog
noun
: a usually temporary state of diminished mental capacity marked by inability to concentrate or to think or reason clearly
This brain fog can be a result of being overly stressed, tired, carrying extra weight, consuming too many calories or consistently consuming a diet poor in nutrients.—Kylie Helgens, The Gazette (Cedar Rapids, Iowa)
Kylie Helgens, The Gazette (Cedar Rapids, Iowa)Love words? Need even more definitions?
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