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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That fluctuation of hormones causes this whole litany of symptoms, like hot flashes, night sweats, brain fog, joint pain, dry skin, brittle hair, hair loss, so many things.
—
Tribune News Service, Baltimore Sun, 2 Mar. 2026
Grief can manifest as physical symptoms, such as brain fog, memory loss, stomach upset and fatigue.
—Alyssa Goldberg, USA Today, 26 Feb. 2026
SSRIs’ common side effects include upset stomach, brain fog, and fatigue.
—Kff Health News, Oc Register, 23 Feb. 2026
SSRIs' common side effects include upset stomach, brain fog, and fatigue.
—CBS News, 23 Feb. 2026
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Tribune News Service, Baltimore Sun, 2 Mar. 2026
Grief can manifest as physical symptoms, such as brain fog, memory loss, stomach upset and fatigue.
—Alyssa Goldberg, USA Today, 26 Feb. 2026
SSRIs’ common side effects include upset stomach, brain fog, and fatigue.
—Kff Health News, Oc Register, 23 Feb. 2026
SSRIs' common side effects include upset stomach, brain fog, and fatigue.
—CBS News, 23 Feb. 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 9 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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