brain fog

Also brain-fog,

[breyn fog, fawg]

noun

1. a mental state marked by difficulty remembering, concentrating, or thinking clearly, often caused by exhaustion, stress, or illness: For new parents, fatigue and brain fog seem inevitable.

   He had so much brain fog that a single thought felt impossible.

   For new parents, fatigue and brain fog seem inevitable.

   Research has found that long COVID can cause brain fog and memory loss.

Word History and Origins

Origin of brain fog¹

First recorded in 1850–55; brain ( def. ) + fog ¹ ( def. )

Example Sentences

Fatigue, joint pain, rashes, brain fog or tingling in the hands and feet can seem like normal signs of aging—but they may also point to an autoimmune disease.

Read more on The Wall Street Journal

I entered menopause, and my new brain fog only added to the haze.

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Her brain fog and some other symptoms remain.

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"Brain fog" isn't a medical term.

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There can of course be other neurological conditions for which brain fog can be a symptom too.

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