The concept of phlegm-fluid containing ancestral wisdom provides an astonishingly persuasive explanation from the perspective of modern medicine as well. Brain fog syndrome, medically known as brain fog, is considered to arise from complex causes including chronic inflammation, gut health imbalances, mitochondrial dysfunction, neurotransmitter imbalances, and the accumulation of waste products in the brain. All of these are actually closely connected to the roles played by phlegm-fluid.
First is chronic inflammation. The accumulation of phlegm-fluid in the body is similar to a state of sustained chronic low-grade inflammation. When gut health deteriorates, the intestinal wall becomes damaged, leading to leaky gut syndrome. As undigested food residues and toxins travel through the bloodstream throughout the whole body, they can trigger inflammatory responses in organs, including the brain. Microglia in the brain become excessively activated, inducing neuroinflammation, which leads to cognitive decline.
Second is the hypofunction of the glymphatic system, the brain's waste clearance system. While we sleep, the brain undergoes a brain washing process where cerebrospinal fluid flows between brain tissue to wash away wastes accumulated during the day, such as beta-amyloid. If sleep deprivation, chronic stress, or circulatory disorders prevent this glymphatic system from functioning smoothly, wastes accumulate in the brain, brain function declines, and brain fog symptoms can worsen. The expression in Donguibogam that phlegm-fluid blocks the clear qi of the head aligns directly with the modern interpretation of waste accumulation in the brain.
Third is metabolic dysfunction. When repeated blood sugar spikes occur or insulin resistance develops, the brain cannot properly utilize needed glucose, directly leading to an energy deficiency in brain cells. A brain lacking energy struggles to exert proper concentration and memory, which can also be viewed as the result of a turbid metabolic flow in the body, just like phlegm-fluid. Furthermore, endocrine imbalances such as hypothyroidism and adrenal fatigue are cited as major causes of brain fog; these likewise signify states where the body's regulatory functions are weakened, making it easy for wastes to accumulate.
As such, the groggy and stuffy brain fog syndrome is not simply a temporarily fatigued state, but a complex problem arising from broken overall bodily balance and accumulated waste products. From the perspective of phlegm-fluid, an integrative approach is needed to improve circulation in the body, reduce inflammation, and optimize brain function.
