Post COVID Brain Fog: The Consistent Mystery

Aug 1, 2022 | Greg Vanichkachorn | @drvan | Comments (43)

In the early days of the pandemic, patients with Post COVID Syndrome (PCS) reported troubles with their thinking. This came to be known as brain fog, and since then the term has become of permanent part of the PCS discussion. Yet, if you look up the word brain fog in a medical dictionary, you won’t find any information. That’s because brain fog is not a medical term and it does not have a set definition. However, if we go past the term brain fog and ask patients with PCS what specific thinking problems they have, patients describe amazingly similar troubles.

The most common complaint is trouble finding words during speech. Patients often describe feeling the word they want to say is on the tip of their tongue, but they just can’t proceed.  This makes communicating very difficult, which is quite frustrating, especially when suffering a medical condition.

The next frequent problem involves short term memory. The classic story we hear from patients is that they will go into a room to find something, and not remember what they were looking for when they get there.  Or they will listen to new information, such as driving directions, and not be able to retain the details.

Finally, patients have problems with multitasking.  Doing even simple things at the same time are much harder with PCS. A common example is having troubles grocery shopping while having a conversation.

This pattern of thinking difficulty PCS is surprisingly consistent. It is also not rare. In fact, 45% of our patients in the COVID Activity Rehabilitation Program (CARP) report suffering from brain fog.  And unfortunately, of all the symptoms we get to help patients with, thinking troubles are often one of the most stressful symptoms, because it causes problems with work and relationships.

Fortunately, we are now starting to unravel the mystery around brain fog.  For example, there are now studies showing that after COVID, there can be brain structure changes, explaining the dysfunction we see.  We are also making progress in how brain fog is objectively described. For example, a research study at Mayo Clinic is currently trialing a new virtual test for brain fog. This 25-minute test allows our team to identify specific areas of troubled thinking in patients with PCS. This is important because once we know the problems, we can help patients develop specific strategies to overcome their troubles. And with each test, we are contributing to a growing database that helps describe brain fog in PCS more accurately.

What should you do if you feel you have troubles with thinking after a COVID infection? First, take care of yourself.  Eat well, hydrate, and get good sleep.  If that doesn’t help, reach out to your treatment provider. We have found that patients that are able to get help sooner, get better faster and more completely.

Together, we can help clear out the brain fog of PCS, and shed more light on the path to better health.

Read more about managing symptoms through early care. Learn tips on talking with your health care provider about post COVID syndrome, and connect with other people in the Post-COVID Recovery & COVID-19 support group.

Interested in more newsfeed posts like this? Go to the Post-COVID Recovery blog.


What treatment did you get for the brain fog

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No treatment aside from months of
Physical Therapy.
No help.
Hospitalized 3 times.
Once for 3 days.
Attributed to speech malfunction. No treatment.
Many MRI’s.


After getting covid, I forgot things easily and could not focus, I went to the bathroom 3 to 4 times per night, I felt extremely tired even after a long night sleep. Doctors checked me up and could not find the reason. But after some months of getting enough oxygen level, I feel energized in the morning, my memory is getting better by 90% -95%, I am still trying to reach to 100% level. I now can work long hours without feeling tired. This is all that I have been doing: walking at least 6000 steps every morning, often practicing 4-7-8 breathing technique during day time (I read about this technique from CNN), use Medcline pillow (you can use an alternate brand, as long as it is elevated, it is good for you), humidifier for my bedroom, light salt water (after brushing teeth), neck/muscle stretching and I wear Oxygen ring monitor overnight. When you wear an oxygen ring monitor, you will know what position of sleeping can help to get the best oxygen level. To my knowledge, lacking oxygen makes our brain foggy, tired, all of our organs are affected dramatically since blood cannot be delivered to all parts of our body. A year ago, I myself thought I got Alhzeimer at an early age but now I am back to normal so I hope my info helps you too. Daily 4/7/8 Mindfulness breathing before bedtime truly helps. Good luck to you all!!!

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One item to add- I use a V-PAP machine for sleep apnea, prescribed for me because at night I tend to exhale but not immediately inhale creating an oxygen shortage. The V-PAP actually pushes air into my lungs. I have found I wake up more refreshed and with better sleep than before I started using it; and better than a C-PAP which I used before which makes oxygen available but does not push the air into your lungs. Good luck!


I went to a neuropsychologist for memory testing, thinking I had Brain Fog...she asked me if I was on a ventilator...I replied NO. She said, "Well you can't have Brain Fog unless you were on a Ventilator! I'm a Doctor, I know this!!" Hmmm! I've known several friends and acquaintances that have been treated for brain fog AND were never on a Ventilator. I call BS on this...I had Covid in 2020 and am still trying to find answers. Also experiencing a chronic cough (which I didn't have before) and horrible time trying to find my words--in my mind, I know what I want to say but it still won't com out! I used to be quite verbal but don't want to talk much anymore! I retired from my job (of 40 years) in a hospital laboratory in fear of making a mistake! I'm 63.

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