healthHealth and Medicine

"Brain Fog" Is Afflicting A Surprising Amount Of People After Covid-19


Tom Hale

Senior Journalist

clockOct 14 2020, 18:17 UTC

Mary Long/

As the pandemic continues to roll on, it’s now clear that Covid-19 is often much more than a cough and a fever, but can involve a broad array of symptoms that lurk long-after the worst of the infection resolves. Among the many symptoms this entails, from heavy chests to headaches, it appears that a significant number of people are continuing to suffer from a lingering feeling of “brain fog” after recovering from Covid-19. 

It's still too early to say how common this experience might be, although a number of case studies have suggested it could be surprisingly prevalent. One study asked 120 people who were hospitalized with Covid-19 how they felt over 100 days after being first admitted, concluding that half of the recovered patients felt fatigued and over a third said they were experiencing memory loss. A recent preliminary study from South Korea surveyed 65 recovered Covid-19 patients and found that 91.1 percent of them were suffering from at least one lasting side-effect, most often tiredness followed by lack of concentration or "brain fog".


Part of the difficulty in understanding brain fog is that it can appear to affect people in different ways, but it’s loosely defined as a fatigued feeling involving tiredness, low mood, memory loss, confusion, and difficulties with concentration. As explained by the sufferers of this unusual condition, it can take a real toll on their everyday life and well-being. 

“I joke, ‘Well, Covid has eaten my brain, because I can’t remember how to remember words, keep track of medication.’ My brain just feels like there’s a fog,” Hanna Lockman, a 32-year-old from Kentucky who suffered from after-effects of Covid-19 for at least five months, told the Journal of the American Medical Association (JAMA).

“I feel like I have dementia," Lisa Mizelle, a 53-year-old nurse practitioner from Alabama who fell ill with Covid-19 in July, told The New York Times in a recent story. “I leave the room and I can’t remember what the patient just said.” 

However, like many of the long-term effects of Covid-19, brain fog is a bit of a mystery to scientists.


Some have suggested it might be akin to post-viral fatigue syndrome. People recovering from other nasty infections often report feeling heavily fatigued for weeks or even months after recovering, as if the body is taking time to recover from its arduous battle with the illness. Although this might be a likely suspect, many of the finer points surrounding post-viral fatigue syndrome are not agreed upon by researchers nor widely understood, let alone when it’s in the context of Covid-19.

Others suggest the mystery of brain fog could go deeper. Covid-19 is unusual because SARS-CoV-2 can breach the blood-brain barrier and infect neurons, causing damage to the brain. Perhaps, as some have alluded to, the symptoms of fatigue and memory loss are somehow linked to damage, swelling, and inflammation of brain tissues.

One study published earlier this month even argued that lingering brain fog and other neurological symptoms after Covid-19 recovery may actually be due to post-traumatic stress disorder (PTSD). They reviewed data from the previous SARS and MERS coronavirus outbreaks and found that survivors had a heightened risk for PTSD, leading them to suggest that this could perhaps explain the persistent cognitive and emotional difficulties found in Covid-19 survivors. 

The cause, for now, remains uncertain. In the meantime, those who have battled brain fog have stressed that it’s important that the symptom – and the many other experiences seen by “Covid long haulers” – is recognized by both the medical world and society as a whole. 


"This stuff is real. People are ill. Doctors need to stop diagnosing this as anxiety. We have messed up before, lets’ not do it again with long term covid-19 illness," Paul Garner, a professor at the Liverpool School of Tropical Medicine who suffered from persisting symptoms for months post-Covid, wrote in a blog post for the British Medical Journal (the BMJ).

healthHealth and Medicine
  • tag
  • virus,

  • pandemic,

  • neurological,

  • brain fog,

  • covid-19,

  • SARS-CoV-2,

  • long-Covid