The link between COVID-19 and brain fog

We’re very familiar with the common symptoms of COVID-19 (SARS-CoV-2), which include a fever, cough, shortness of breath, and fatigue. But up to 25% of people who contracted COVID-19 also reported neurological symptoms [1] – including “brain fog.”

In some cases, this cognitive impairment can last weeks or even months, even after recovering from SARS-CoV-2. Read on to understand what brain fog is, and its connection to COVID-19 – especially long COVID symptoms that persist even after a person is no longer sick.

What is brain fog?

Brain fog can occur under several different circumstances, such as sleep deprivation, sickness, or concussion. The term often describes slow or sluggish thinking, or feeling “spaced out.” [2] While not an official medical diagnosis, brain fog is recognised as a condition that includes symptoms [3] such as

  • Forgetfulness and other memory problems
  • Unclear thinking
  • Distractedness and poor concentration
  • Headaches
  • Confusion

Brain fog normally resolves itself once you’ve returned to a healthy routine, particularly if it’s a result of poor sleep or stress. But for people who’ve suffered COVID-19, that brain fog may persist for weeks or months after the other symptoms (fever, cough, fatigue) have gone away.

It’s essential to note that brain fog is different from fatigue. Fatigue is a sense of severe physical tiredness, as if you have no energy. You may also feel a strong desire to go to sleep. [4] Brain fog, on the other hand, is a cognitive impairment that affects your thinking and mental awareness.

Long COVID and brain fog

At the onset, one hospital found that 42.2% of patients manifested neurological symptoms at the onset of their sickness. [5] One of the most frequent manifestations was mild encephalopathy – impaired cognition. And there is now increasing evidence that encephalopathy causes subtle but prevalent psychological issues long after the initial COVID symptoms have disappeared.

Encephalopathy is “any diffuse disease that alters brain function or structure.” [6] This encephalopathy can trigger brain fog, since its common neurological symptoms include memory loss and cognitive impairment, as well as the inability to concentrate.

COVID-19 can also cause a level of oxygen deprivation in the brain. [7] This lack of oxygen can cause damage to the brain, leading to cognitive impairment comparable to a “moderate traumatic brain injury.”

Both encephalopathy and oxygen deprivation affect the intricate neural networks of your brain, impeding and upsetting the flow of information. Imagine your brain as a factory that has had some of its machines or workers incapacitated – it can still function, but much slower and with more effort.

This dysfunction can cause you to forget activities earlier in the day, or to process information at a slower rate than usual. You may struggle with complex details or fail to remember things you need to do.

This cognitive impairment can linger for several weeks or even months post-infection, at which point it becomes a symptom of “Long COVID.” This has lasting consequences on a person’s physical and mental health.

Fortunately, the large majority of patients find they recover from brain fog over 6–9 months. [8] However, if you have pre-existing neurological conditions such as dementia, this lessens the chances of a full recovery. There is no cure for post-COVID brain fog, but there are actions you can take to combat the condition and minimise its effects.

Combatting Brain Fog

There’s no sure-fire way to rid yourself of brain fog, but you can boost your mental alertness and well-being with certain activities and supplements.

1 – Exercise

Any aerobic activity, even just walking for 20–30 minutes a day, can increase your blood flow. This increases the amount of oxygen directed to your brain and helps it function. If you’re recovering from COVID, start slow – maybe 5 minutes a day, a few days a week. Then you can slowly build up to 30 minutes a day, 5 days a week.

2 – Diet and Supplements

Minimising the amount of processed foods and sugar can improve your diet, which will boost your overall physical health. Consult a registered dietitian to see what foods and drinks they recommend that will aid your cognitive function.

You may also want to speak with your general practitioner and see if you can take Vitamin D supplements to support your brain functions. Alternatively, you can take in more Vitamin D by going out into the sun.

3 – Sleep

Sleep is the body’s way of recovering and recharging for another day of activities. It allows your body to heal and your brain to rest. It’s essential that you get enough sleep for your age group to ensure your brain can function at its peak.

4 – Less tobacco and alcohol

Both substances negatively affect your cognition, especially alcohol. Drinking in moderation is mostly harmless, but excessive intake impairs your ability to think clearly and rationally. Avoiding both smoking and drinking will lessen adverse effects on your brain.

5 – Therapy

Seeing a registered psychiatrist may help, since they are professionally trained to handle cases of psychological and mental impairment. Your psychiatrist may recommend brain exercises such as puzzles and chess, and may also introduce coping mechanisms that will help you function despite the brain fog.

For older patients, they may also recommend cognitive therapy to improve brain function. [9]

Improving Your Mental Health

Mental health is just as significant as our physical health, and it’s important to care for our brain and our cognitive functions. If you find yourself affected by brain fog during and after contracting COVID-19, it’s essential that you seek medical attention as soon as possible to address this cognitive impairment.

Brain fog may have adverse effects on our ability to function day-to-day, but it’s not permanent and you can take steps to make it less debilitating. You may feel like the road to recovery is long, but celebrate the progress you make at each turn – and don’t stop striving to improve.

References:

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7798003/ 
[2] https://www.health.harvard.edu/blog/brain-fog-memory-and-attention-after-covid-19-202203172707 
[3] https://www.healthline.com/health/covid-brain-fog#about
[4] https://medlineplus.gov/ency/article/003088.htm 
[5] https://onlinelibrary.wiley.com/doi/full/10.1002/acn3.51210
[6] https://www.ninds.nih.gov/health-information/disorders/encephalopathy 
[7] https://onlinelibrary.wiley.com/doi/full/10.1111/bpa.12889
[8] https://www.lifespan.org/lifespan-living/what-post-covid-brain-fog-and-how-can-you-recover
[9] https://www.washingtonpost.com/health/2022/08/22/covid-brain-fog-rehab-aging/

Photograph: Tomasz Makowski/Shutterstock

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The information included in this article is for informational purposes only. The purpose of this webpage is to promote broad consumer understanding and knowledge of various health topics. It is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified health care provider with any questions you may have regarding a medical condition or treatment and before undertaking a new health care regimen, and never disregard professional medical advice or delay in seeking it because of something you have read on this website.