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Brain Fog as Metaphor

Novelists can help describe the experience of illness.

Key points

  • Brain fog may not be the best metaphor for the enduring effects of COVID-19.
  • In medicine, describing your symptoms accurately can mean the difference between life and death.
  • Gifted writers can help people describe the psychological and emotional experience of illness.

In mid-February, COVID-19 caught me. Because I’d been vaccinated three times, I thought I had a cold, or maybe the flu (against which I’d also been vaccinated). My ear ached, my throat hurt, and I was emptying more than a box of Kleenex each day. At one point, my head hurt so badly that I considered decapitation. My temperature reached 100, impressive in a cold-blooded creature who rarely breaks 98. When I got up at night to drink a glass of water, I shook with cold for almost 30 minutes although I was lying under two comforters. Thanks to isolation and masking, I couldn’t remember the last time I had had a cold; maybe sometime in 2019

“Gee,” I thought, “these colds are way worse than I remember.”

More compelling than the stuffiness and aches was a feeling hard to describe. An eeriness. A fear. A sense of life dimming. A sense that I was becoming a ghost and falling out of life.

Such feelings are worth investigating because in medicine, describing your symptoms accurately can mean the difference between life and death. The effects of COVID-19 on mental life, inseparable from bodily life, can help health care workers understand what COVID-19 is and how it works.

In me, as in many people who have recovered from COVID-19, this mental dimming has persisted. In a popular metaphor, this mental state is known as “brain fog.” The metaphor doesn’t satisfy me, and in describing how COVID-19 affects mental life, I think we can do better. In the quest to describe strange, inner feelings with medical implications, literature can help.

Source: Portrait of Charlotte Brontë by George Richmond, 1850/Wikimedia Commons, Public Domain
Portrait of Charlotte Brontë by George Richmond, 1850.
Source: Portrait of Charlotte Brontë by George Richmond, 1850/Wikimedia Commons, Public Domain

In Villette, a novel of 1853, Charlotte Brontë’s protagonist Lucy Snowe wanders through a city late at night, uncertain where she wants to go. Many readers know Brontë’s Jane Eyre (1847), but fewer know Villette, a narratively complex love story that involves a courageous teacher, a scheming headmistress, and a ghost nun.

Lucy ventures out at night not once but twice. The first time, her students have gone home for vacation, and for weeks, she has been living nearly alone at the private school where she teaches. Depressed, sick, suffering alternately from insomnia and nightmares, Lucy yields to a compulsion to go out: “One evening—and I was not delirious; I was in my sane mind, I got up—I dressed myself, weak and shaking. The solitude and the stillness of the long dormitory could not be borne any longer” (Brontë I: 231). In her wanderings, Lucy, a devout Protestant, comes upon a Catholic church and asks a priest to hear her confession. He kindly refuses, and after leaving the church, Lucy collapses in a storm, leading to a transformative break in the narrative. Like some of Edgar Allan Poe’s characters, Lucy uses a word, “delirious,” to characterize a mental state she denies having. As she heads out into the wind and rain, she says in a parenthetical aside, “I could not be delirious, for I had sense and recollection to put on warm clothing” (Brontë I: 232). Her repeated denials suggest that sick, sleep-deprived, wet, cold, starved Lucy really is delirious.

The second time that Lucy wanders into Villette at night, she is on drugs. In the nightmare that preceded the first episode, she feels herself forced to drink a bitter draught; in the second episode, the nightmare comes true when a servant sent by the headmistress gives Lucy a drink to make her sleep—except that it doesn’t work. “Instead of stupor, came excitement,” Lucy tells readers. “I became alive to new thought—to reverie peculiar in coloring. A gathering call ran among the faculties, their bugles sang, their trumpets rang an untimely summons” (Brontë II: 305). Lucy rises, sneaks out of school, and walks to the city center, where she finds that “Villette is one blaze, one broad illumination; the whole world seems abroad; moonlight and heaven are banished; the town, by her own flambeaux, beholds her own splendor … It is a strange scene, stranger than dreams” (Brontë II: 309). “Delirium” fits Lucy’s mental state better in this second night adventure, since she feels overexcited. Her episodes of night wandering relate to each other like yin and yang; the first dark and depressed, the second bright and energetic. Lucy’s two bouts of night-wandering share a quality that brought them to mind when I tried to describe my COVID-19 state. On both occasions, Lucy comes across as a ghost wandering a world in which she seems to have no place.

Last February, in about the same shape as Lucy, I thought that movement and fresh air would do me good. On a Sunday night in Berlin, I bundled up (see, reader, I was not delirious) and headed out into the darkness, strong wind, and mid-30s temperatures, seeking something good to eat for dinner. I wandered a street of bright restaurants and shops, which I regarded with confusion. I entered a convenience store that sold only mixes of alcohol, sugar, salt, and fat; I hovered outside a vegan café, uncertain what to ask for. “I belong in a hospital,” I thought. Common sense told me to go home, and on the way, I passed a COVID-19 test center. I didn’t have the strength to pull out my phone and struggle to enter data with numb fingers while a young technician watched impatiently. Luckily, I made it home without collapsing and had positive antigen and PCR tests the next day. Only after I got the result did I realize I could smell nearly nothing, even when I stuck my nose in the peanut butter jar.

When I tried to tell a friend how COVID-19 felt, “delirium” was the first word that came to mind. “Ah!” he said. “So it’s affecting you neurologically.” But “delirium” wasn’t the right word. The Mayo Clinic defines delirium as “a serious disturbance in mental abilities that results in confused thinking and reduced awareness of the environment” (“Delirium”). On that awful night, I had enough awareness to know that I should come in from the cold and that chips and candy wouldn’t help me. Probably Brontë had offered me the word “delirious,” since it was Lucy Snowe who came to mind. I knew only that I felt like Lucy: unseen, spectral, not quite there, so that if passers-by had touched me, their hands would have passed right through me.

To some degree, this feeling of not-quite-thereness has persisted two months after COVID-19. I worked all through quarantine and have continued to work each day, but I feel so tired, I could lie down on the ground and sleep for a hundred years. I seem functional and haven’t made too many bad decisions (that I know of), but if my mind were a gas burner, it would be lowered to a faint glow. Another friend pointed out my lack of a control in my claim that COVID-19 has exhausted me. “I haven’t had COVID-19,” he said, “and I’m exhausted, too.” Uncontrolled, introspective evidence can’t be used to build medical knowledge.

Or can it? In Narrative Medicine: Honoring the Stories of Illness, physician and literary scholar Rita Charon shows how greatly medical knowledge depends on telling and interpreting stories (Charon). Rather than lowering the status of medical knowledge, which is science-based, Charon’s argument raises it by realistically assessing medicine’s reliance on narrative patterns as well as controlled studies. Well-written fiction that invites readers to enter characters’ minds results from years of close observation in artists who use language expertly to make their characters’ experiences "feel real" (Auyoung).

Source: "Fog" by sumidiot/Creative Commons license CC BY-SA 2.0
Source: "Fog" by sumidiot/Creative Commons license CC BY-SA 2.0

As a description of a mental state, “brain fog” is a lay expression, “not a scientific or medical term” (Budson). Its underlying metaphor belongs to an ancient tradition that Western learning shares with many cultures worldwide, in which light represents knowledge, wisdom, and awareness; and darkness represents ignorance. An “enlightened” person knows how the world works and understands how his or her actions will affect others. Fog impairs vision, and by metaphorical implication, a person experiencing brain fog can’t see or understand the world clearly. As a description of someone’s mental state during and post-COVID-19, that metaphor may or may not be apt.

My own descriptions of having COVID-19 (eeriness, dimness) draw on the same metaphorical family of darkness and light. I can’t say they’re much better than “brain fog,” but, assisted by Brontë, they do suggest the fear of a COVID-19 sufferer in a way that “brain fog” can’t. Lucy Snowe walks out at night to seek life and to keep herself alive. By calling my altered state “eeriness,” I was trying to convey a realization that death was near. My three vaccinations and the tireless work of scientists who developed COVID-19 vaccines ensured that my case was mild, and I survived. If I hadn’t had those three vaccinations, I might well have died. My symptoms were insignificant compared to those of people who have been hospitalized and put on ventilators. But as one of the more than 500 million people worldwide (that we know of) who have had COVID-19, I believe we need a language that conveys the psychological experience of the disease as accurately as possible, one that includes the emotions of illness. Perceptive writers such as Charlotte Brontë can help explain how living with a virus feels.


Brontë, C. [Bell, C.] (1853). Villette. 2 vols. Leipzig: Tauchnitz.

Budson, A. E. (2021.) “What is COVID-19 brain fog—and how can you clear it?” Harvard Health Publishing. Harvard Medical School.….

Charon, R. (2006). Narrative Medicine: Honoring the Stories of Illness. New York: Oxford University Press.

“Delirium.” (2022). Mayo Clinic.….

Auyoung, E. (2018). When Fiction Feels Real: Representation and the Reading Mind. New York: Oxford University Press.

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