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
Recent Examples on the Web
At the same time, my primary care doctor and gynecologist suggested my symptoms — brain fog, fatigue and cognitive changes — were caused by menopause.
—
Shon Lowe, Twin Cities, 26 Mar. 2026
Social media is rife with influencers and life coaches selling supplements to relieve night sweats, clear brain fog and sustain libido.
—Ann Juliano, The Conversation, 24 Mar. 2026
When levels drop, a woman can experience fatigue, brain fog, and tingling in the hands and feet without being anemic at all.
—Allison Palmer, Sacbee.com, 20 Mar. 2026
Researchers at Mass General Brigham examined whether high doses of vitamin D could influence COVID-19 outcomes, including the risk of developing long COVID, a condition in which symptoms such as fatigue, shortness of breath and brain fog continue weeks or months after the initial infection.
—Kelly McGreal, FOXNews.com, 15 Mar. 2026
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Shon Lowe, Twin Cities, 26 Mar. 2026
Social media is rife with influencers and life coaches selling supplements to relieve night sweats, clear brain fog and sustain libido.
—Ann Juliano, The Conversation, 24 Mar. 2026
When levels drop, a woman can experience fatigue, brain fog, and tingling in the hands and feet without being anemic at all.
—Allison Palmer, Sacbee.com, 20 Mar. 2026
Researchers at Mass General Brigham examined whether high doses of vitamin D could influence COVID-19 outcomes, including the risk of developing long COVID, a condition in which symptoms such as fatigue, shortness of breath and brain fog continue weeks or months after the initial infection.
—Kelly McGreal, FOXNews.com, 15 Mar. 2026
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 31 Mar. 2026.
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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