Prof. Seungho Baek's Medical Insight

The kidney is the body’s deepest reserve in Korean medicine. Its master function is to store essence (Jing), from which kidney Qi, Yin, and Yang all arise. This guide covers essence and its two sources, why kidney Yin/Yang/Qi deficiencies all trace to essence, the kidney’s rule over growth and reproduction, and its grasping of Qi and governance of water.

The liver in Korean medicine has two great functions: it stores the blood and it courses the Qi. This guide explains both — the liver as the body’s blood bank and metabolic manager, and its coursing role that keeps Qi, emotions, bile, digestion, and blood flow all moving — and why the two must balance each other.

After the spleen and stomach, the rest of the digestive tract: the small intestine, which receives food, transforms it further, and separates the clear from the turbid; and the large intestine, which conducts the residue, absorbs leftover fluid, and forms stool. This guide also explains the close liver–large intestine connection.

The spleen and stomach are the digestive core of Korean medicine — and, because they make Qi and Blood from food, its most fundamental organs. This guide explains the raising-and-lowering pair, the stomach’s work of receiving and ripening, and the spleen’s three jobs: transforming and transporting, raising the clear, and governing the blood.

After the heart comes the lung. In Korean medicine the lung works in two directions — dispersing Qi outward and descending it down — and governs Qi for the whole body: respiration, Qi generation, the water passages, and the gathering of blood. This guide also explains why the lung sits at the surface and comes in twos.

The heart is where Korean medicine’s organ theory begins. It has two governing roles — it rules the blood and vessels, and it rules the mind. This guide explains both, the old distinction between the “blood heart” and the “spirit heart,” and the protective role of the pericardium.

After Qi, Blood, and Body Fluids come the organs. Korean medicine sorts the internal organs into three classes by function — the storing Zang, the passing-through Fu, and a third, unusual group called the extraordinary organs (brain, marrow, bone, vessels, gallbladder, and uterus). This guide lays out the classification and what makes the extraordinary organs distinct.

Body Fluids are the third of Korean medicine’s three substances — all the normal fluids of the body. This foundational guide explains what Body Fluids are (and what they become when they turn abnormal), how they are made and moved by the spleen, lung, and kidney, what they do, and how they relate to Blood and Qi.

Blood is the second of Korean medicine’s three substances. This foundational guide explains how Blood is made (food essence, with the spleen, kidney, heart, and lung each playing a part), what Blood does (nourishing and moistening body and mind), how it moves, and why Blood and Qi are an inseparable pair.

Qi is the first of the three basic substances of Korean medicine. This foundational guide explains what Qi is (its formless and formed states), where it comes from (clear air and food essence), the main kinds of Qi, and the functions it performs — propulsion, warming, transformation, nourishment, containment, and defense.