My head feels foggy and I can't concentrate... Is it 'brain fog'? | Long COVID

1. “I just thought I was tired…”

Hello, this is Baekrokdam Korean Medicine Clinic.

Have you had any of these experiences recently?

• Forgetting what you were about to say during a meeting
• Sitting idly and missing important tasks
• Tasks that used to be easy to manage suddenly feel overwhelming
• Unable to recall the name of an acquaintance, stumbling over your words

And then you find yourself saying:

“It feels like my brain is foggy these days; I’m dazed and can’t think straight.”

The topic we’ll be discussing today is exactly this: ‘Brain Fog’.

This is different from simple fatigue or distraction. It’s a peculiar state where your body feels fine, but your brain seems separately exhausted. In the post-COVID era, this phenomenon is being experienced by more and more people.

2. Was the term 'Brain Fog' always around?

The term ‘Brain Fog’ is not actually a recently coined neologism. Although not a formal medical diagnosis, the term has been commonly used in certain fields for decades.

It was first used in the fields of Functional Medicine and in communities of patients with chronic illnesses. For example, patients suffering from Chronic Fatigue Syndrome (CFS), Fibromyalgia, or autoimmune diseases frequently used this phrase to describe their condition.

Doctors also informally used the term 'brain fog' when it was difficult to describe symptoms as merely "concentration problems" or "cognitive decline." In essence, it was a clinical slang that effectively described the phenomenon, even if not medically defined.

Then, in 2020, after the COVID-19 pandemic, this term became a 'formal medical topic.' Numerous COVID patients consistently reported:

• “My sense of smell is back, but my head feels foggy.”
• “I can’t remember things well.”
• “I can’t concentrate when I try to work.”

Now, the WHO also mentions brain fog as part of 'long COVID' symptoms, and papers with 'Brain Fog' directly in their titles are appearing in medical journals. In other words, the entire world has witnessed the process of an informal term becoming formalized.

3. Symptom Patterns — Different from simple fatigue

Brain fog cannot be explained by simply saying 'I'm tired.' It is much more complex, subtle, and subjectively distressing.

Typical symptoms include:

• Difficulty concentrating
• Blurry memory
• Difficulty finding words
• Mental fogginess
• Significantly slower work processing speed
• Increased errors and decreased confidence

The important thing is that these symptoms are not simply due to a lack of physical energy. Patients commonly say:

“I don't feel refreshed even after sleeping.”
“My head still feels heavy even after a vacation.”

When this state persists, it leads to a breakdown of self-efficacy. Confidence disappears, work stress intensifies, and it can sometimes be accompanied by depression and anxiety. Ultimately, it's a state of living as if you're ill, even if it's not a recognized disease. That is brain fog.

4. Why has it become so common after COVID?

To understand this question, we need to know how the coronavirus works. COVID-19 invades cells through 'ACE2 receptors.' These receptors are present in the lungs, heart, organs, kidneys, blood vessels, and also in the endothelial cells of brain blood vessels.

In other words, COVID is not just a respiratory infection, but a virus that disrupts the entire vascular, autonomic nervous, and metabolic systems.

Even after seeming to recover from the infection, subtle inflammatory responses often linger, blood circulation and oxygen supply may not be smooth, and the autonomic nervous system's regulatory capacity may be diminished.

As a result:

• Sleep doesn't lead to recovery
• You feel dazed during the day,
• Concentration breaks down,
• And performing daily tasks becomes overwhelming.

Especially since even young, healthy individuals report these symptoms, it's difficult to attribute it to simple 'physical decline.'

5. How is it viewed from a Korean Medical perspective?

In Korean medicine, this state has long been referred to as ‘yeobyeong’ (餘病), meaning a residual illness where, even after the disease seems to have resolved, the lingering energy of the illness delays full recovery. Or 'yeoyeol michung' (餘熱未清), which refers to inflammation or turbid energy that has not been completely cleared.

There is also the term ‘damtak jonoe’ (痰濁阻腦), which describes a concept where turbid energy or phlegm within the body obstructs the clear function of the brain.

→ This reflects the Korean medical understanding that brain function can become blurry even without structural lesions in the brain itself.

In modern terms, this can be linked to concepts such as autonomic nervous system imbalance, impaired mitochondrial energy metabolism, and dysfunction of the gut-brain axis.

That is, brain fog is viewed not merely as a problem of the head, but as a problem where the entire body fails to deliver clear energy to the brain.

6. How should it be treated?

Korean medical treatment proceeds along three main axes:

1. Acupuncture Therapy – To awaken the brain and stabilize the autonomic nervous system
   • Points like Baekhoe, Sasinchong, Indang → for opening brain portals and enhancing clarity
   • Naegwan, Taechung → for emotional stability and mind-body connection
   • Pungnyung, Joksamni → for clearing turbid phlegm and restoring digestion
   • Sinsu, Myeongmun, Gihae → for replenishing vital energy and restoring overall energy
2. Herbal Medicine Therapy – To "open orifices and refresh the spirit" (개규성신), "tonify heart, spleen, and kidney" (보심비신), and "regulate phlegm and transform turbidity" (조담화탁)
   • Strong-scented herbs (e.g., Acorus gramineus, Polygala tenuifolia, Poria cocos) → to stimulate the brain and restore senses
   • Long-term: customized prescriptions based on Heart-Spleen Deficiency or Kidney Essence Deficiency patterns
   • Traditional remedies like 'Jukyeo' (Bamboo Shavings) are also used to aid post-illness recovery
3. Lifestyle Routine Design
   • Morning sunlight exposure → to restore the melatonin-serotonin rhythm
   • Simple brain training → repetitive tasks like 'planning, sequencing, remembering'
   • Management of sleep, digestion, and emotional fluctuations → key conditions for brain fog recovery

7. A disease where despair arrives before the illness itself

Brain fog is not 'brain failure'; it is 'functional confusion' and 'delayed recovery.' Therefore, it is reversible.

However, the emotional distress caused by these symptoms is immense. It feels like dementia, is difficult to explain to others, and medical tests show nothing, which makes people even more exhausted.

What is needed at such times is:

“Your symptoms are real.”

Korean medicine is a discipline that observes and regulates the overall flow of the body, even when the specific cause is unknown. And in these situations, it can be the most powerful tool.

Don't suffer through brain fog alone. It's time for proper interpretation and approach.

#BrainFog #LongCOVID