It is stated that the five Zang organs have their respective positions, with the Lung alone residing in the upper region. Therefore, the *Neijing* (Classic of Internal Medicine) states: "The Qi of Heaven communicates with the Lung," and further says: "The Lung governs the skin and hair." It serves as the Huagai (Canopy of the Five Zang Organs). Among the five Zang organs, it corresponds to Po (Corporeal Soul), which enters and exits together with Jing (Essence). In the five moral dispositions, it corresponds to Yi (Righteousness), which overcomes external things and makes decisions. Its orifice opens into the nose; thus, its fluid is Ti (Nasal Discharge), which flows out before saliva follows tears. In vocal sounds, it corresponds to Ku (Crying); thus, its emotion is You (Sorrow/Grief), which is characterized by Yin austerity and a desolate sentiment. Its color is white because it belongs to Metal; its taste is Xin (Pungent) because it signifies the completion of things. As for its correspondence to Dryness in Heaven, Metal in Earth, Shang (Metal Note) in musical tones, and Xing (Fishy Odor) in smells, all are related to seasons, numbers, Qi, and categories.

I shall discuss it from the perspective of meridians and interior-exterior relationships: The Hand-Taiyin Lung Meridian and the Hand-Yangming Large Intestine Meridian constitute the interior-exterior pairing of these Zang-Fu organs. The Hand-Taiyin Meridian originates in the Middle Jiao (Middle Burner), descends to connect with the Large Intestine, circles around the stomach opening, passes through the diaphragm, and attaches to the Lung. From the Fei Xi (Lung System, including trachea and larynx), it emerges horizontally under the axilla, descends along the medial aspect of the arm, running anterior to the Hand-Shaoyin Heart Meridian and Hand-Jueyin Pericardium Meridian, reaches the elbow center, follows the medial forearm along the lower border of the radius, enters the Cun Kou (Radial Pulse site), ascends to Yu Ji (LU10), and exits at the tip of the thumb. Its branch diverges from behind the wrist, goes straight to the medial side of the index finger, and exits at its tip. When Yin and Yang are balanced, meridians are harmonious, and Qi and Blood fluctuate moderately without excess or deficiency, no bias is observed. Once balance is lost, diseases arise. Excess constitutes "Youyu" (Surplus), which is pathological; deficiency constitutes "Bují" (Insufficiency), which is also pathological. Pathologies of surplus are termed Fei Shi (Lung Excess); pathologies of insufficiency are termed Fei Xu (Lung Deficiency). Symptoms of Lung Excess include panting, cough, rebellious Qi, shoulder and back pain, sweating, and pain in the medial thigh, knee, and tibial region. Symptoms of Lung Deficiency include cold pain in the shoulder and back, shortness of breath with inability to sigh deeply, chest fullness, and dry throat. Diseases manifest according to the locations where meridian Qi circulates. Therapeutic principles dictate that Excess patterns should be treated with Draining methods, while Deficiency patterns should be treated with Tonifying methods; Surplus should be reduced, and Insufficiency should be supplemented. This is the general principle.

Regarding pulse diagnosis, the normal pulse of the Hand-Taiyin Meridian is Floating, Choppy, and Short. If other pulses appear, balance is lost. Thus, the Lung has a Mother-Child relationship with the Spleen and Kidney, and a Husband-Wife relationship with the Heart and Liver. If the pulse is Hong (Surging) and large yet Huan (Moderate), it indicates being overcome by the Mother organ. If it is Chen (Deep) and Ru (Soft) yet Hua (Slippery), it indicates being overcome by the Child organ. If it is Xian (Wiry) and Chang (Long), it indicates being overcome by the Wife organ. If it is Fu (Floating) and Da (Large) yet Hong (Surging), it indicates being overcome by the Husband organ. If the Mother overcomes the Child, it is called Xu Xie (Deficient Evil); although diseased, it is easy to treat. If the Child overcomes the Mother, it is called Shi Xie (Excess Evil); although diseased, it will heal spontaneously. If the Wife overcomes the Husband, it is called Wei Xie (Minor Evil); although diseased, it will recover quickly. If the Husband overcomes the Wife, it is called Zei Xie (Robber Evil); this is a great reversal and is difficult to cure. One must examine Deficiency and Excess to apply Tonification or Draining. Examining treatment methods represents the general overview.