Have you ever felt like you were listening to someone talk but not really? Your head feels fuzzy. It’s like you’re sleepwalking but awake. It’s a lack of sharp memory and focus. Like you need to try harder to do better in life. Everything is hazy, and you feel foggy in your thoughts. We all have these moments at work, in meetings, on calls, etc.

Brain fog, to me, feels like when my brain slows down its inputs and outputs. Often times forgetting what my next task was or why I walked into my room. When I’m at my best, I have no issues expressing myself in clear words. But when my brain is hazy, I feel tired easily. On normal days, my brain runs smoothly with 50 tabs open, but its crazy when my brain fails to open even a single tab. On days like this, I want to give up and stay in bed till it passes (funnily, on other days, east coast winters do the job for me).

Brain fog is caused due to lack of sleep, nutrient deficiencies, lack of exercise, hormonal changes, and stress. There can also be underlying causes for brain fog such as anemia, depression, migraines, alzheimer’s disease. But sometimes, its cause can be as simple as eating too much or too little. I have brain fog after eating a meal that is highly concentrated on carbohydrates (such as rice – think about a bowl full of rajma chawal!!), it’s practically impossible for me to continue doing work after.


It’s 2021, a year after the COVID-19 pandemic hit the world. COVID-19 truly slowed down all our lives. We went from physically going into work everyday to staying at home more often leading to lesser physical activity. My mental health has been better than ever, but my physical health ‘evolved’ from being fit (before the pandemic) to being super lazy (now, everyday). The world forcefully transitioned to zoom and other online meeting apps. On today’s date, 110 million people have been infected by COVID-19, out of which 85 million people have recovered. Brain fog is a neurological symptom of COVID that has been under research since its first few recovered patients. Slightly different from normal brain fog, COVID brain fog can be explained as continued fatigue and forgetfulness. How does a disease that affects lungs lead to brain fog and other neurological disorders?

According to an article on COVID brain fog, about a third of recovered COVID patients have neurological symptoms such as strokes and seizures. Researchers at Memorial Sloan Kettering said that they started treating neurological COVID symptoms the same as any other inflamed brain damage symptoms until they found a solid difference in diagnosis and treatment between the two. The patients who came in were given the usual MRI/CT scans. When nothing unusual was found in the brain scans, the researchers at MSK – Dr. Adrienne Boire (MD, PhD) and Dr. Jan Remsik ordered spinal taps to find if the SARS-CoV-2 had entered the cerebrospinal fluid, 13 out of 18 patients tested negative for this test. But, here’s the catch – even though they didn’t find the virus in these patients’ CSF, their CSF had high levels of cytokines, which explained the symptoms.

Cytokines are signaling proteins that have the capacity to affect proliferation and differentiation in immune and non-immune cells. They play a role in damaged tissue repair, cancer development and progression, cell replication and apoptosis, and immune reaction modulation. A cytokine that is highly expressed in COVID brain is interleukin 1-beta.

COVID brain is still under research. There are multiple pathways by which the virus can enter the central nervous system, but what’s really cool is the role of the Blood Brain Barrier which acts as a roadblock for various bacteria, viruses and parasites.

What does brain fog feel like to you? Do you know someone with COVID brain fog?

PS – this article is not to tell you that having brain fog necessarily means having COVID.

Jan Remsik, Jessica A. Wilcox, N. Esther Babady, Tracy A. McMillen, Behroze A. Vachha, Neil A. Halpern, Vikram Dhawan, Marc Rosenblum, Christine A. Iacobuzio-Donahue, Edward K. Avila, Bianca Santomasso, Adrienne Boire. Inflammatory Leptomeningeal Cytokines Mediate COVID-19 Neurologic Symptoms in Cancer PatientsCancer Cell, 2021; 39 (2): 276 DOI: 10.1016/j.ccell.2021.01.007

McGeorge, F. (2021, February 17). COVID brain fog: What it is and what it means for virus patients. WDIV. https://www.clickondetroit.com/health/2021/02/17/covid-brain-fog-what-it-is-and-what-it-means-for-virus-patients/

Foster JR. The functions of cytokines and their uses in toxicology. Int J Exp Pathol. 2001;82(3):171-192. doi:10.1046/j.1365-2613.2001.iep0082-0171-x

Higuera, V. (2018, May 23). 6 Possible Causes of Brain Fog. Healthline. https://www.healthline.com/health/brain-fog#causes

Memorial Sloan Kettering Cancer Center. (2021, February 9). What’s driving ‘brain fog’ in people with COVID-19. ScienceDaily. Retrieved February 18, 2021 from http://www.sciencedaily.com/releases/2021/02/210209121044.htm

Fishman, L. (2021, February 3). Can COVID-19 Cause Brain Fog? NewYork-Presbyterian. https://healthmatters.nyp.org/what-is-causing-covid-brain-fog/

Coronavirus Update (Live): 110,770,445 Cases and 2,449,382 Deaths from COVID-19 Virus Pandemic – Worldometer. (n.d.). Worldometer. Retrieved February 18, 2021, from https://www.worldometers.info/coronavirus/#countries

Egler, J. (2020, August 13). 5 Ways to Beat Brain Fog. Parsley Health. https://www.parsleyhealth.com/blog/beat-brain-fog/