What Korean medicine describes as liver yang hyperactivity is very closely linked to autonomic nervous system imbalance in modern medicine. In particular, it is deeply tied to hyperactivation of the hypothalamic-pituitary-adrenal axis, which regulates the stress response. When we experience stress, the brain signals the release of hormones such as cortisol and adrenaline. These hormones elevate heart rate and constrict blood vessels to temporarily prepare the body for an emergency, raising blood pressure in the process. It mirrors the way the body readies itself to fight or flee when confronted by a wild beast.
Modern life, however, confronts us not with wild animals, but with chronic stress from relentless work, relationship challenges, and an uncertain future. When this stress response continues over time, the sympathetic nerve within the autonomic nervous system becomes excessively active. Sustained hyperactivation of the sympathetic nerve damages the vascular endothelium and increases the release of substances that constrict blood vessels. In time, the elasticity of the blood vessels diminishes, resistance to blood flow increases, and blood pressure becomes chronically elevated. In this process, excessive pressure is also placed on cerebral blood vessels, which may bring on headaches, dizziness, and tinnitus.
Furthermore, chronic stress can cause endothelial dysfunction, impairing vasodilation and encouraging inflammatory responses that raise the risk of arteriosclerosis. Because the body interprets stress as an ongoing danger and continues in fight-or-flight mode, blood pressure does not easily settle, and added anxiety or restlessness can perpetuate a difficult cycle. Rather than only relying on an antihypertensive, it is genuinely important to consider why the liver, the general of the body, keeps venting this heat, to resolve the underlying stress, and to restore autonomic nervous system balance.
