brain fog

American  

[breyn fog, fawg] / ˈbreɪn ˌfɒg, ˌfɔg /

Also brain-fog,

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.

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Etymology

Origin of brain fog

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.

From The Wall Street Journal

These, in turn, can trigger relentless fatigue, brain fog, postural orthostatic tachycardia syndrome, and other autonomic nervous system problems, and post-exertional malaise, or the inability to recover after physical or mental activity.

From Slate

Brain fog goes away, statistically.

From Salon

"She still gets pains in her legs, that's probably the worst thing along with the fatigue. There's breathlessness, chest and tummy pain, brain fog and she gets quite light-headed at times."

From BBC

But the damage did not stop there: across the globe, survivors of the initial viral infection reported "long flu" symptoms — profound fatigue, brain fog, depression, tremors, sleeplessness, and a litany of neurological disorders.

From Salon