We have all experienced days when our mind feels cloudy, concentration is out of reach or simple tasks seem unusually difficult. These moments are often described as “brain fog.” Although not a formal medical diagnosis, brain fog can disrupt your daily life and make you feel disconnected or unproductive. But East Asian Medicine (EAM) can provide some insight into what causes brain fog and how to deal with it.
The term brain fog covers a consistent cluster of cognitive symptoms: difficulty finding words mid-sentence, an inability to hold a train of thought, slowed information processing and a kind of mental resistance that makes ordinary tasks feel heavier than they should. Patients with long COVID, post-infectious fatigue, chronic stress and hormonal disruption all report versions of the same experience.
Clinicians often attribute these complaints to depression, anxiety or fatigue rather than recognizing cognitive impairment as a distinct process. This leaves a significant patient population without a framework for understanding what is happening or a pathway toward treatment. But what the research is increasingly clear on is that brain fog is not a psychological phenomenon. It is a biological one and the mechanisms are becoming well understood.
This is how brain fog is broken down from a biological standpoint:
1. Microglial Activation and Neuroinflammation – Microglia are the brain’s resident immune cells. In healthy conditions they perform surveillance and repair. When chronically activated, by infection, psychological stress, environmental toxins or sustained systemic inflammation, they release pro-inflammatory signaling molecules including tumor necrosis factor alpha (TNF-alpha), interleukin-1 beta and interleukin-6. These cytokines impair synaptic plasticity, the process by which neurons strengthen connections and slow neural transmission in the prefrontal cortex and hippocampus, the regions responsible for working memory, word retrieval and executive function.
2. Blood-Brain Barrier Disruption – The blood-brain barrier is the filtering system that keeps inflammatory mediators in the peripheral circulation from entering the central nervous system. When it is compromised, peripheral immune cells and neurotoxic compounds infiltrate the brain, extending and amplifying the neuroinflammatory response.
3. BDNF Depletion – Brain-derived neurotrophic factor (BDNF) is the brain’s primary growth and repair signal. Think of it as fertilizer for neurons. It supports the formation of new brain cells in the memory centers of the brain, strengthens the connections between existing neurons and maintains the flexibility that allows the brain to retrieve words, consolidate memories and shift attention efficiently. Chronic stress, systemic inflammation, poor sleep and physical inactivity all suppress BDNF production. When levels fall, cognitive performance follows in ways that feel exactly like brain fog.
4. Gut-Brain Axis – The connection between gut microbiome health and cognitive function is no longer speculative. When the gut’s bacterial ecosystem falls out of balance, gut dysbiosis occurs. Gut dysbiosis reduces production of several signaling molecules the brain depends on, including short-chain fatty acids, gamma-aminobutyric acid (GABA, a calming neurotransmitter) and the building blocks for serotonin. A disrupted gut also becomes more permeable, allowing inflammatory compounds to leak into the bloodstream and eventually reach the brain.
In EAM, brain fog is commonly associated with imbalances in qi, blood flow and organ systems, particularly the spleen, heart, liver and kidneys. Qi stagnation (blocked energy), blood deficiency or the presence of dampness (internal “heaviness” or excessive moisture) may contribute to brain fog by impeding the natural flow of energy and nourishment to the brain.
Each TCM diagnosis involves a personalized assessment of symptoms, considering factors such as lifestyle, emotional health and physical well-being. The three most common EAM causes of brain fog are overall qi deficiency, heart blood and qi deficiency and liver qi stagnation.
Qi deficiency is when the qi is weakened due to poor diet or stress. This may lead to an accumulation of dampness, which creates a feeling of heaviness and mental cloudiness. This is the most common cause of brain fog.
The heart houses the mind and regulates mental functions. An imbalance in heart qi and blood can result in symptoms of anxiety, poor focus and forgetfulness. This is classified as heart blood and qi deficiency.
The liver plays a key role in maintaining the free flow of qi. Emotional stress, frustration or lack of movement can cause liver qi stagnation, leading to irritability, tension and fogginess.
The good news is that acupuncture has been shown to improve brain fog, cognitive dysfunction and strengthen the gut-brain axis. Studies exploring acupuncture’s role in brain health are uncovering some intriguing patterns. One of the most consistent findings is its effect on circulation, especially cerebral blood flow. The brain depends on a steady supply of oxygen and nutrients. And even small improvements in circulation can have a meaningful impact on how clearly we think and process information.
There’s also evidence suggesting acupuncture may influence neurotransmitters aka the chemical messengers that regulate mood, focus and memory. At the same time, it appears to help calm neuroinflammation, a low-grade inflammatory process increasingly linked to cognitive decline and neurodegenerative disease. These aren’t dramatic, overnight changes. They’re subtle shifts that, over time, may help support a more resilient and adaptable brain.
Another study published in 2025, examined acupuncture’s effects on the gut-brain axis and found that treatments helped restore healthy microbial balance, raised BDNF levels through changes in gene expression and reduced microglial activation through this gut-to-brain pathway.
But studies aren’t the only way to measure the benefits of acupuncture. For most patients, it is more about how they feel versus the testing. In a fast-moving, always-connected world, the nervous system rarely gets a chance to reset and the body stays locked in a low-level “fight or flight” state, driven by stress hormones like cortisol. Over time, this can interfere with sleep, disrupt focus and make even simple tasks feel overwhelming. Acupuncture works in part by helping to shift the body into the parasympathetic state—the “rest and restore” mode where healing, digestion and mental clarity are more accessible.
If you are someone who is frequently plagued by brain fog or cognitive decline, why not consider giving acupuncture a try? It will most likely take some time and multiple treatments, but the being able to stay mentally clear is the reward that follows.