How, then, can heart fire in the body be explained through modern science? Let me explain it simply. What Donguibogam describes as heart fire is very closely connected to chronic stress and emotional burnout in modern medicine. When we are exposed to continuous stress, our body perceives it as a crisis situation and activates the hypothalamic-pituitary-adrenal axis in the brain. In this process, stress hormones such as cortisol are excessively secreted.
While cortisol helps in coping with crises in the short term, over the long term it exerts toxicity on our brain. In particular, it negatively affects the function and structure of the hippocampus, which handles emotion and memory, and the frontal lobe, which governs planning and decision-making. It causes brain cells to atrophy and can even suppress the generation of new brain cells. It is like hot flames slowly burning and damaging vital areas of the brain.
Furthermore, chronic stress leads to the depletion of neurotransmitters such as serotonin for well-being, dopamine for motivation, and norepinephrine for arousal and focus. Just as heart fire consumes heart qi, stress depletes these vital substances in the brain. When these substances become deficient, motivation in life fades, and lethargy and depression—where one cannot feel pleasure—intensify, much like a car that has run completely out of fuel.
Recent studies also reveal that neuroinflammation and mitochondrial dysfunction are deeply linked to depression. Chronic stress triggers a systemic inflammatory response, and these inflammatory substances can cross the blood-brain barrier to affect the brain, leading to reduced brain function. In addition, when the function of mitochondria—the powerhouses of our body—declines, cells cannot produce energy properly, causing one to fall into chronic fatigue and lethargy. Ultimately, the heart fire in Donguibogam accurately pinpoints the deep-rooted principles of burnout syndrome and depression created by the complex stress response and brain functional changes identified by modern science.
