l Written by Dr. Nam Tae Gwang at Tong-in Korean Medicine Clinic
"I know I was supposed to do something, but I can't remember what it was."
"I keep reading the same page, and nothing sinks in."
"It feels like there's a fog in my head — everything is hazy and I can't concentrate."
These days, people increasingly describe this kind of experience as brain fog — a term that refers not to a specific diagnosis, but to a general state in which the mind feels unclear and memory or concentration is noticeably diminished.
So why does this happen? And what kinds of treatment can help?
Brain Fog: A Term Made Familiar by COVID-19
Brain fog — a broad term covering reduced attention, memory, processing speed, and executive function — became widely recognised after COVID-19, as growing numbers of people reported persistent fatigue alongside difficulty concentrating and retaining information. The World Health Organization has identified cognitive impairment as one of the key symptoms of long COVID.
That said, forgetting things more often than usual does not necessarily point to dementia or serious neurological disease. Relatively common and correctable factors — stress, anxiety, low mood, and poor sleep — can all affect memory and concentration.
What Causes Brain Fog?
Brain fog rarely stems from a single cause. More often, it arises from several overlapping factors.
1. Sleep deprivation and chronic fatigue.
Without adequate sleep, the brain struggles to consolidate the information it took in during the day and convert it into lasting memory. Even if you sleep for long hours, frequent waking, snoring, sleep apnoea, or waking up unrefreshed can all reduce daytime concentration.
2. Excessive stress and tension.
When worry and rumination are constant, the brain's resources are continually occupied with processing anxiety and maintaining alertness. As a result, it becomes harder to focus on tasks at hand — words don't come as easily, and small things are forgotten more often.
3. Post-infection recovery delays.
After illnesses such as COVID-19, brain fog can persist alongside fatigue, sleep disturbance, and headaches. A large study published in the New England Journal of Medicine in 2024 found that people with lingering post-COVID symptoms showed objectively measurable cognitive deficits.
4. Chronic pain and physical discomfort.
When the body is persistently dealing with pain, digestive issues, dizziness, or palpitations, attention is continuously drawn away from the task at hand. In many of these cases, the underlying memory itself may not have declined significantly — rather, information was never fully absorbed in the first place.
5. Correctable physical causes.
Cervical instability or misalignment, vitamin B12 deficiency, and hypothyroidism can all cause fatigue alongside reduced memory and concentration. If symptoms persist, rather than attributing everything to stress, it is worth seeking a proper evaluation to identify any underlying cause.
When to Seek Medical Advice
If brain fog has persisted for several weeks or is beginning to affect your work or daily life, it is worth investigating the cause. In particular, the following situations should not be written off as simple fatigue or stress:
- Getting lost in familiar places
- Repeatedly forgetting appointments and important responsibilities
- Memory or judgement that is noticeably worsening over time
- Sudden confusion accompanied by slurred speech or weakness on one side of the body
- Severe headache, fainting, seizures, or changes in consciousness
Sudden speech difficulties, one-sided weakness, or altered consciousness may indicate a medical emergency — seek immediate care. If memory problems are consistently affecting daily life, a clinical evaluation is recommended.
How Korean Medicine Treats Brain Fog
Rather than treating brain fog as a single named condition, Korean medicine examines the full picture of underlying causes and accompanying symptoms — an approach that complements conventional medical evaluation well.
For example, someone who tires easily and has reduced appetite and digestive function may be assessed as experiencing Qi deficiency (氣虛) — a state in which the body's overall energy is depleted, leaving insufficient resources to sustain mental clarity.
Conversely, someone carrying significant stress and worry, chest tightness, or difficulty falling asleep may be seen as experiencing Qi stagnation (氣滯) — a state in which the flow of energy is blocked, often expressing itself as tension, irritability, and difficulty unwinding.
In other words, two people experiencing the same brain fog symptoms may arrive at very different diagnoses — and Korean medicine tailors its treatment accordingly.
Acupuncture to Regulate Tension and Support Sleep
Acupuncture is used to address the range of factors that often accompany brain fog: sleep disturbance, fatigue, tension, headaches, and excessive tightness in the neck and shoulders.
Multiple randomised sham-controlled trials have found that acupuncture can improve sleep quality and reduce insomnia severity in patients with chronic sleep difficulties. Where sleep disturbance is a primary driver of brain fog, improving sleep is a meaningful first step.
Herbal Medicine to Support Cognitive Function
Korean herbal medicine is not prescribed uniformly. The practitioner considers the full picture — degree of fatigue, sleep quality, digestive health, stress levels, and symptoms such as dizziness or palpitations — before formulating a prescription tailored to each individual.
Some small-scale randomised controlled trials involving ginseng-based preparations have reported improvements in working memory, attention, and mental fatigue in healthy adults — though the evidence remains early-stage. The right formula depends on your specific pattern, constitution, and any medications you are currently taking.
Managing Brain Fog in Daily Life
1. Start by checking your sleep rhythm.
Keeping a consistent sleep and wake schedule is foundational. Reducing smartphone use and caffeine intake before bed can also help. If you frequently wake during the night, or snoring or sleep apnoea is suspected, having those assessed separately is worthwhile.
2. Focus on one thing at a time.
Trying to manage multiple tasks at once when brain fog is present tends to increase errors. Breaking important tasks into smaller units and making active use of reminders and notes can significantly reduce cognitive load.
This is not giving up on your memory — it is a way of reducing the burden on the brain so that more energy is available for recovery.
3. Move within your limits.
Aerobic exercise has been shown in some research to support cognitive functions such as executive processing. Starting with walking or light cycling and gradually adjusting based on how the body responds is a sensible approach.
However, if fatigue and mental haziness worsen significantly for more than a day after activity, rest takes priority. In long COVID and chronic fatigue syndrome, symptoms can worsen after both physical and mental exertion. Pacing — balancing activity and rest within your current energy limits — is often necessary to avoid setbacks.
4. Store memories outside your head.
Using a planner, notebook, or phone reminders means you are not relying solely on your internal memory to track everything. Designating fixed places for important items is also helpful. When brain fog is present, offloading information to external tools is a practical way to reduce mental load and free up energy for recovery.
Brain fog is rarely a simple matter of declining memory.
It more often reflects the body's overall recovery state — shaped by sleep, stress, fatigue, and physical health working together.
Rather than pushing harder to concentrate or reaching for caffeine, it is worth identifying what is currently slowing recovery down.
If symptoms persist or begin to affect daily life, it may be the body signalling that it needs support. Visiting a Korean medicine clinic or conventional medical practice is a good place to start.
> Considering a visit? Explore Tong-in Korean Medicine Clinic, Seoul
[QnA]
Q. What is the difference between brain fog and dementia?
Brain fog is a temporary decline in cognitive function brought on by correctable causes such as poor sleep, stress, or post-infection recovery — and it often improves once those causes are addressed. Dementia, by contrast, is a neurodegenerative condition in which memory and judgement progressively worsen over time. If you are getting lost in familiar places or repeatedly forgetting important commitments, a clinical evaluation is recommended.
Q. Can brain fog resolve on its own?
It depends on the cause. Where stress or poor sleep is the primary driver, addressing those factors often leads to meaningful improvement. However, brain fog that persists after COVID-19 can continue for several months or longer, and relying on natural recovery alone may not be sufficient. If symptoms persist for more than a few weeks, it is worth seeking a consultation.
Q. Can Korean medicine help with brain fog?
Korean medicine can be a helpful approach. Rather than treating brain fog as an isolated symptom, Korean medicine practitioners assess accompanying factors — including sleep, fatigue, digestion, and stress — before formulating a plan that may combine acupuncture and herbal medicine. Where sleep disturbance is a key driver, research suggests that acupuncture may indirectly support cognitive recovery by improving sleep quality.
Because the approach is tailored to each person's constitution and symptoms, an individualized assessment is important.
Q. Are there supplements or foods that help with brain fog?
If brain fog is linked to vitamin B12 deficiency or hypothyroidism, addressing those deficiencies can help. However, the evidence that specific supplements directly improve brain fog remains limited. A balanced diet that keeps blood sugar stable, combined with adequate hydration, is a practical foundation for sustained concentration.
| Edited by Sia Shin, The Pylon Square
