The concept recorded in the Donguibogam that excessive thought harms the spleen is actively studied in modern medicine under the name gut-brain axis. It is as if our brain and gut are connected by an invisible hotline, exchanging information in real time. This bidirectional communication system allows emotions and stress felt in the brain to directly affect the gut, while the state of the gut reciprocally influences emotional states in the brain.
When we experience stress, the brain secretes stress hormones such as cortisol, which directly affect the autonomic nervous system leading to the stomach. In particular, stress suppresses the activity of the parasympathetic nervous system, or vagus nerve, which oversees digestion and relaxes the stomach, while excessively activating the sympathetic nerve, which tenses the body and triggers the fight-or-flight response. When this happens, gastrointestinal motility becomes irregular or slows, digestive enzyme secretion decreases, and gastric acid secretion is disrupted. Some individuals experience heartburn from excessive gastric acid secretion caused by stress, while others experience bloating and indigestion because insufficient gastric acid leaves food lingering in the stomach for too long. In addition, as the mucus layer protecting the stomach wall declines in function, the stomach lining becomes more sensitive, leading to visceral hypersensitivity where one feels noticeable pain or discomfort from even minor stimulation. The stomach may register pain even when food merely moves through it.
Nervous gastritis, or functional dyspepsia in modern medicine, is the result of this complex process. Even when an endoscopy is performed, specific inflammation or an ulcer is often absent. While there is no structural lesion in the stomach itself, digestive function fails to operate normally due to communication disruptions between the brain and gut along with autonomic nervous system imbalance. However, because such functional issues can lead to structural problems like actual stomach wall inflammation or reflux esophagitis if they become chronic, they should not be ignored. Stress is not merely a mental condition; it is a physical response that alters gastrointestinal motility, secretory function, and stomach wall sensitivity. That is why patients are often advised to calm their mind before trying to calm their stomach. The brain and gut continuously influence each other. When the mind is anxious, the stomach feels unsettled; when the mind is calm, the stomach rests comfortably. Addressing this root cause, which cannot be resolved by an acid suppressor or a digestant alone, is key to managing nervous gastritis.
