Introduction to TCM

Basics of TCM

  • Yin-Yang | Five Elements

Zang-Fu Theories

  • Zang Organs | Fu Organs

Classification of Antineoplastic Herbal Medicines

Characteristics of Herbal Medicines


  • By Auscultation & Olfaction
  • By Inspection


Theories of Channels (Meridians) and Collaterals

Reference: A Modern View of the Immune System

Differentiation of Syndromes

  • 8 Principles | 6 Channels 4 Stages
  • Syndromes of Zang-Fu Organs


  • Exogenous | Pestilential | Emotional
  • Pathogenic Factors

Materia Medica

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The lung is situated in the chest, connects with the throat and opens into the nose. Its main physiological functions and indicators are: (1) dominating qi and controlling respiration; (2) dominating the dispersion and descent of qi; (3) regulating water passage; and (4) connecting externally with skin and hair. It also has an exterior and interior relationship with the large intestine.

Dominating Qi and Controlling Respiration

This function is composed of two aspects, dominating the qi (air) of respiration and controlling respiration. It is the organ where the respiratory air is internally and externally exchanged; clean qi from the environment is drawn in and exchanged for waste qi. The other aspect of the lung's function has a close relationship with the formation of collective (zong) qi which is the combination of essential qi transformed from water and food with the inhaled qi of the lung. Collective qi accumulates in the chest, then flows up to the throat to control respiration. Since all the blood vessels lead to the lung, collective qi is distributed throughout the body to nourish the tissues and organs in maintaining the body's normal functional activities. If the lung function is normal, there is an unobstructed circulation of qi, with even and harmonious breathing. If there is a deficiency of lung qi, there will be feeble respiration, uneven breathing, weak speech, lassitude, etc.

Dominating the Function of Dispersion and Descent

The function of dispersion and descent involved the distribution of qi, blood, and body fluid to the zang-fu organs, the channel-collaterals, muscles, skin, and hair. Descending function means that lung qi is clear and descends. The lung is situated in the upper jiao (thoracic cavity) and its qi normally flow downward. If lung qi fails to descend and instead ascends, then the qi will pool together in the lung and be manifested by stuffy chest, cough, asthma, etc.

The two functions of dispersion and descent, although opposite to each other, act in unison. If the dispersing function is not normal, the lung qi will not flow downward and vice versa. Harmonious, downward flowing of lung qi allows for an unobstructed respiratory tract, uniform breathing, and provides a normal exchange of air in the lung. In this was the lung can distribute qi, blood, and body fluid to the entire body, transport waste water down to the urinary bladder, transform it into urine and excrete it.

In pathology, the two functions of dispersion and descent affect each other. If external pathogenic factors attack the exterior of the body, then the lung qi fails to spread. This leads to pathological changes like cough and asthma due to the failure of descending lung qi. If pathogenic phlegm obstructs the lung, it will bring about an abnormal flowing of lung qi leading to pathological changes such as cough, fullness of chest, and gurgling with sputum.

Dominating the Skin and Hair and Regulating Water Passages

Here the skin and hair represent the entire body surface including skin, sweat gland pores, and hire which act as a barrier against the invasion of exogenous pathogenic factors. In this way the lung is understood to have a close connection with the skin and hair. Through the dispersing function of the lung the essentials of food and water are transported to the body surface in order to nourish the skin, hair, and muscles. The lung also spreads defensive (wei) qi to the body's surface, "warms the tissues between the skin and muscles, replenishes the skin, nourishes the muscles, and regulates the opening and closing of the pores." Therefore the lung has the ability to protect the organic body by defending against the invasion of exogenous pathogenic factors.

Pathologically there is an mutual influencing relationship between the lung, and skin and hair. For example, the invasion of exogenous pathogenic factors proceeds from the skin and hair to the lung. The manifestations are aversion to cold, fever, nasal obstruction, nasal discharge, cough, or even asthma. These are signs of the lung's failure to spread defensive qi to the body surface. If lung qi is weak and deficient, defensive qi is not dispersed and the essential nutrients to the skin and hair are not distributed. This not only causes rough skin and dry hair, but also hypoactivity of the defensive qi.

The organic body is easily attacked by external pathogenic factors. Defensive qi controls the opening and closing of the pores. When there is lung qi deficiency the body surface will be weak and manifests the symptom of spontaneous sweating. If external pathogenic cold attacks the body's exterior the lung will lose its function of dispersing and descending and the pores will close not allowing the formation of sweat.

Regulating the water passages means that the lung regulates water circulation and excretion, and keeps the water passages clear. The lung's dispersing function circulates throughout the body the nutrients which have been removed from food and water. Part of the fluid is discharged as sweat and by the descending function of the lung. Another part of the fluid is continually sent down to the kidney and then, by the qi function of the kidney, sent to the urinary bladder to be discharged. Thus the lung is also known as the "upper source of water."

Opening into the Nose

The nose is the gateway of respiration. Clear, unobstructed nasal breathing and smelling rely upon the good functioning of the lung qi. Since the nose is the opening of the lung, it will also be a passage for the invasion of external pathogenic heat which may attack the lung. Pathologically the lung also has a close relation with the nose. For example, if external pathogenic wind and cold block the lung, it will cause a dysfunction of lung dispersion manifested by stuffy nose, nasal discharge, dull olfaction, etc. If pathogenic heat accumulates in the lung there will be nasal discomfort caused by coarse breathing or dyspnea. In treating this condition, the dispersing method with pungent medicinal herbs is used to act on the lung and nose. Acupuncture stimulation is applied on ear acupoint "lung" to treat nasal polypus, chronic rhinitis, etc. The above-mentioned facts demonstrate the close relationship between the lung and the nose. The throat is also a gateway of respiration, and a vocal organ. The lung channel passes through the throat, so smooth qi flow and a clear voice are directly affected by the functions of lung qi. Hence when there is a pathological change of the lung, it will cause hoarseness of voice, sore throat, or other pathological changes.

Related Subjects

Read more on other Zang Organs: Heart, Spleen, Liver, and Kidney.

Traditional Chinese medicine pages by Raymond Cheng, PhD DPA

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Raymond Cheng, PhD DPA FRSA FRSPH

March 28, 2014.

