Part 1
Philip A.M. Rogers MRCVS
e-mail :
1982, updated 1993, 1995
Postgraduate Course in Veterinary AP, Dublin, 1996


Nature and the body are unities, in which mutual control and harmony are maintained by creation (anabolism) and destruction (catabolism). Five Phase Theory extends Yin-Yang Theory, in which all things in nature are classified into five basic types or Correspondences: Fire, Earth, Metal, Water, Wood. The Phases and their Correspondences interact in predictable ways. As Yin and Yang have anabolic and catabolic aspects, so also have the Five Phases. Thus, the Five Phases have a Sheng (Mother-Son, anabolic, creative, nourishing = ->) and a Ko (Grandmother-Grandson, catabolic, controlling, destructive, = X) Cycle.

The Sheng Cycle is: Fire -> Earth -> Metal -> Water -> Wood -> Fire. In the Sheng Cycle, Fire is the Mother of (feeds or strengthens) Earth and Metal is the Son of (is nourished by) Earth.

The Ko Cycle is : Fire X Metal X Wood X Earth X Water X Fire. In the Ko Cycle, Fire is the Grandmother of (dominates or controls) Earth and Metal is the Grandson of (is brought under control by) Earth.

Each Phase (or ELEMENT) relates to a specific Yin/Yang pair of the Channel-Organ System (COS) and to a wide list of Correspondences (function, emotion, excretion, body tissue, season, food etc). Thus, Fire relates to the COSs Heart and Small Intestine (HT and SI) and their Correspondences (sweat, tongue, speech, face, circulation, excitability, psyche, bitter taste, red, summer, south etc).

Disease involves imbalance (Excess, Deficiency or Stagnation) of Qi in one or more COSs. Therapy involves restoration of the balance of Qi. Each Channel has 5 special Points, corresponding to each of the Five Phases and a Luo (Passage) Point. These Points are used to transfer Qi between COSs when there is one or more with Qi Excess and an equal number with Qi Deficiency. This restores the balance and harmony of Qi. One usually stimulates the Deficient COS, to draw Qi from its Yin/Yang mate (via the Luo Point) or from another COS (via the Sheng or Ko Cycle). Any Deficiency thus created in the donor COS is filled from an Excess elsewhere. However, if only one COS is involved, it may be Tonified by needling its Mother Point, or Sedated by needling its Son Point.

Five Phase Theory has many implications in medicine. However, the theory is incomplete and it has its limitations. It is a useful guide to aetiology, diagnosis, prognosis and therapy but it is not absolutely necessary for therapeutic success. Knowledge is an ongoing process. While AP can produce good clinical results without a knowledge of the use of Five Phase Theory, the theory enhances the probability of optimal results, especially in complex disease syndromes.


The Traditional Chinese Medical (TCM) law of Yin-Yang is the UNIVERSAL LAW of mutual control by mutual antagonism and dependence of all things. (See the papers on Holistic concepts of health and disease and on Traditional versus modern AP). The interplay of Yin-Yang is an endless cycle of action and interaction.

The concept of cycles is fundamental to TCM. Nothing is static. Nothing is absolute. Everything is dependent on (relative to) everything else. All things must CHANGE. The Five Phase Cycle is another fundamental concept of TCM. In essence, everything and every concept in creation is a manifestation of Qi (energy). Qi has attributes or characteristics of one or more of five basic types, and can transform from one Phase to another. The types or Phases are called: Fire, Earth, Metal, Water, Wood. For instance, suppose you are sitting in your armchair, looking into a fire and meditating on the nature (or type) of Fire. You might see it as primarily heat and light (energy-giving). However, the same fire once was (and still contains an element (Phase) of) living organic material (Wood, peat, coal, methane). As it burns, it produces (and contains an element of) ash (Earth) and mineral residue (Metal) and the hydrogen in most burning fuels is oxidised to Water. Thus Fire also contains aspects (elements, Phases) of the other Phases (Wood, Earth, Metal and Water). In turn, earth and minerals, when fed by Water can produce a new tree (Wood). Thus, all the basic components Fire, Earth, Metal, Water and Wood are needed for (inherent in) every other Phase.

Each Phase has typical characteristics or Correspondences. Each has also its Yang and Yin aspects. The Phases create (engender, nourish, help) one another and destroy (control, restrain, dominate) one another in a ceaseless, dynamic cycle, the dance and rhythm of life and death.

In TCM, the Two Phase (Yin-Yang) and Five Phase Cycles are universal Laws. They are the source and manifestation of evolving creation and destruction in all its aspects. They apply to every aspect of life and politics, art, music, science, philosophy, sociology and medicine. They are primitive (yet ultra-sophisticated) concepts of the balance and inter-dependence of all things. If one Phase becomes imbalanced (too strong or too weak), the whole cycle is upset and disharmony can arise in other Phases and their Correspondences. Restoration of balance depends on recognition of which Phases are upset and the redistribution of Qi between them so as to restore harmony, if this is possible.

The Five Phase Cycle has two major components, the Sheng Cycle (Mother nourishing Son) and the Ko Cycle (Grandmother restraining Grandson). The Sheng is anabolic, creative, nourishing, feeding. The Ko is catabolic, destructive, weakening, controlling.

Sheng Cycle: Things of a Fire nature promote (create or nourish) things of an Earth nature, which promote or create things of a Metal nature etc. The Cycle is Fire -> Earth -> Metal -> Water -> Wood -> Fire.

Sheng mnemonic: To remember the Sheng Cycle, visualise a gardener Watering a seed. The seed grows into a tree. The tree is cut down for fireWood. The Fire produces ashes which could be further refined to produce Metal. The sequence is Water -> Wood -> Fire -> Earth -> Metal -> Water. Because a cycle has no beginning and no end, it is not important which Phase is put at the top of the diagram, but it is usual to put Fire on top because (as will be seen later) four COSs are associated with Fire and the top position is the most aesthetic, as will be seen when the COSs are added to the diagram.

In this Cycle, things of Fire are Mothers of things of Earth (which are Sons of Fire). In turn, things of Earth are Mothers of things of Metal (which are Sons of Earth).

Another Mother and Son concept was discussed elsewhere in relation to the Diurnal Qi Cycle (daily Qi tide) from: LU -> LI -> ST -> SP -> HT -> SI -> BL -> KI -> PC -> TH -> GB -> LV -> LU. In the Qi Cycle, LU is the Qi Mother of LI and BL is the Qi Son of SI etc.

The following diagram shows the relationships between the Phases in the Sheng Cycle. The Sheng Cycle is represented by a clockwise circle. It is continuous, having no beginning and no end. Although Fire creates Earth, Earth is necessary for Fire: (without Earth the succeeding Phases (Metal, Water and Wood) would not be, and Fire itself would die!).



      Wood          Earth



        Water <==  Metal 

The Sheng Cycle is the concept of Interpromotion among Phases: the Mother is necessary for the creation/nourishment of the Son. Thus, the Sheng Cycle is a GROWTH AND PROMOTION (anabolic) Cycle.

Ko Cycle: All growth (Sheng) must be controlled or restrained, otherwise abnormalities like cancer, overpopulation, starvation and crime etc arise. The Ko Cycle is the important controlling or restraining force between the Five Phases. It is a cycle of mutual control-inhibition-restraint. In this cycle things of a Fire nature restrain-control-inhibit things of a Metal nature. Metal restrains Wood etc. The following diagram shows the relationships of the Ko (restraint) Cycle.

The Ko Cycle is: Fire X Metal X Wood X Earth X Water X Fire. It is represented by a clockwise pentagram or star. It is continuous, having no beginning and no end. Although Fire restrains Metal, Metal has some control on Fire also, because without Metal, Water and Wood could not be (in the Sheng Cycle), therefore Fire could not be. Thus the Ko Cycle is a cycle of mutual CONTROL and RESTRAINT (the Grandmother disciplines, brings order to, restrains, the Grandson):



   Wood -----> Earth



    Water     Metal 



Without Sheng (nourishment) there can be no growth and development. Without Ko (restraint), excessive development would be harmful.

Thus, both the Sheng and Ko Cycles are necessary for balance. They represent a state of continuous dynamic anabolism and catabolism respectively. All things in nature must change. In biology, as in nature, nothing is static (i.e.) the system is in continuous movement, one Phase becoming another. During this movement (rhythm) there are active (Yang) and passive (Yin) phases. The combination of Sheng and Ko is represented in the following diagram: ===> represents Sheng Cycle (nourishing, promoting anabolic); ---> represents Ko Cycle (restraining, controlling, catabolic); +++> represents Counteracting (a Reverse Ko) Cycle: Fire X Water X Earth X Wood X Metal X Fire. Earth restrains (controls) Water (in the Ko Cycle) but Water may Counteract on Earth (in the Reverse Ko Cycle):



    Wood -----> Earth



     Water <== Metal 

The balance of growth (Sheng) and restraint (Ko) is necessary for harmony in the system. Thus, by a process of mutual synergism and antagonism, harmony is maintained.


If there is an Excess, Deficiency or Stagnation (Blockage) in one Phase, abnormal phenomena may appear in other Phases because the primary imbalance may Overact or Counteract on other Phases.

Overacting means attacking a Deficient Phase via the Ko route. A Phase with normal Qi, but especially one with an Excess of Qi may attack a Deficient Phase via the Ko Cycle (the Grandmother annoys (or weakens further) the Weak Grandson). A normal (or, especially hyperactive) Grandmother harms the Deficient Grandson Phase. For example, if Wood is Deficient (weak), Metal could Overact on it, thereby exaggerating the problem. If Wood is in Excess, it can Overact on Earth (weaken it). Counteracting is another type of attack by one Phase on another, via the reverse Ko route (the Grandson annoys the Grandmother). If Wood is in Excess it can Overact on Earth and simultaneously can Counteract on Metal. If Wood is Deficient it can be Overacted upon by Metal and be Counteracted upon by Earth at the same time.

The Sheng, Ko, Overacting and Counteracting forces are the basis of all interactions between diseased organs. We will see later that each Phase has a set of Correspondences, including a solid Yin Organ and hollow Yang Bowel. For now, it is sufficient to know that Fire, Earth, Metal, Water and Wood are associated with the Yin COSs HT, SP, LU, KI, LV respectively. Disease in any one of these COSs can have secondary effects on any other member of the group. For instance, Lung disease could be primary. However, it could be secondary to disease in Spleen (Mother (Earth) affecting the Son (Metal) in the Sheng Cycle); to disease in the Kidney (Son (Water) affecting the Mother (Metal) in the Sheng Cycle); to disease in the Liver (Liver (Wood) Counteracting on Liver (Metal)) or to disease in the Heart (Heart (Fire) Overacting on Lung (Metal)).

In summary (so far), Five Phase Theory is a UNIVERSAL THEORY relating types of things in a harmonious, balanced system (the Sheng and Ko Cycles). If one of the Phases becomes too weak or too strong, the entire system can become unbalanced. By Overacting and Counteracting forces, one imbalanced Phase may affect others. Any one Phase may be imbalanced by imbalance in any other Phase. Correction of the balance depends on recognition of the Excess and Deficient parts of the system and in redistributing the Qi to the correct parts of the system to restore harmony. This concept is the first documented concept of Holistic medicine: any one organ is related to, and can influence the functions of, any other organ.

(see the following tables)

Each Phase has a whole series of characteristics associated with it. The following tables show some of these Correspondences. Students who wish to study the Five Phase Theory in depth are referred to standard textbooks (Wu 1973; Connolly 1979; Hsu 1982; Kaptchuk 1983; Porkert 1983; Wiseman et al 1985; Anon 1993).

The Correspondences of the Five Phases may help in diagnosis of health problems by indicating which Phases are imbalanced. For instance, if a human patient has a history of lacrimation, blurred vision and defects in the nails, one might suspect imbalance in the Wood Phase (see tables of Correspondences). If he/she has an angry temperament, shouted a lot and had a history of muscle aches and tendon pain, this would be further evidence of Wood imbalance. Further examination would help to distinguish between LV and GB. For instance, palpation of the bladder Shu (reflex) Points, front Mu (Alarm) Points, Yuan (Source) and TEST Points (see paper on the study techniques) would be very helpful to distinguish between LV and GB. Pulse diagnosis might also suggest that another Phase, for instance Earth, was also imbalanced. For instance, in a liverish patient, a frequent picture might include indigestion, weakness, nausea and Watery eyes. The Qi diagnosis may be LV Excess with ST Deficiency. In Five Phase Theory, the treatment of such a case is very simple. One needle at the Grandmother/Wood Point of ST (ST43) would suffice. By stimulating this point on the Deficient ST COS, Excess Qi is drained from LV (Wood, Yin) to fill the Deficiency in ST (Earth, Yang) via the Ko Cycle. (In Ko Cycle, Wood controls (is the Grandmother of) Earth and therapeutic Qi passes from Yin to Yang (or Yang to Yin) in the Ko Cycle). (Don't worry if you do not understand this example. It will become clearer when you have studied the entire paper).

In the Five Phase Cycle, the following relationships apply to the Channels, their Organ/Bowels, Functions and Correspondences. The Yang COSs appear outside the circle in the diagram. They are: SI=Small intestine; TH=Triple Heater; ST=Stomach; LI=Large Intestine (Colon); BL=Bladder; GB=Gall Bladder. The Yin COSs appear inside the circle. They are: HT=HearT; PC=Pericardium, Circulation-Sex, Heart Constrictor); SP=Spleen-Pancreas; LU=Lung; KI=Kidney; LV=Liver.



                                SI  TH

                                HT  PC

               Wood   GB                     ST  Earth

                         LV               SP 

                            KI          LU  

                  Water   BL              LI   Metal

Note that the linked COSs form a Yin-Yang Pair within each Phase: Fire HT-SI and PC-TH; Earth SP-ST; Metal LU-LI; Water KI-BL and Wood LV-GB. Qi can be transferred from HT to SI (or SI to HT, as required) by the use of the correct Luo (passage) Point, always stimulating the Luo of the Deficient COS to draw Qi from its linked COS. Also, in therapy, the points can help SI problems and vice-versa.

In the Sheng Cycle, HT nourishes SP and SI nourishes ST etc, (i.e.) the Qi in the Sheng Cycle passes from Yin to Yin or from Yang to Yang only. The Qi transfer in the Sheng Cycles is as follows (-> = creates or nourishes):

Sheng Cycle Fire -> Earth -> Metal -> Water -> Wood -> Fire
Yang to Yang transfer SI -> ST -> LI -> BL -> GB -> SI
Yin to Yin transfer HT -> SP -> LU -> KI -> LV -> HT


Correspondence Fire Earth Metal Water Wood
Body fluid,Secretion Sweat Phlegm, saliva Mucus Saliva, urine Tears
Orifice & sense organ controlled Tongue, speech, words Mouth, taste Nose, smell Ears, genitals, anus, urethra, hearing Eyes, vision, foresight
Manifests externally or expands into Face, complexion Lips, mouth, throat, flesh Skin & body Hair on the head Nails
Nourishes or Governs Blood vessels, arteries, blood cir- culation Fatty tissue, muscles Skin & body hair; mucous membranes Bones, teeth; bone marrow; brain Tendons, ligaments, muscles
Main Temperament, emotions Joy, happiness excitability manic depressive extrovert Obsession, worry meditation sympathy, depression greedy Anguish, grief, melancholy negativity, sympathy Fright, fear, timidity, phobias, introversion Anger,irr-itability, depression unstable
Verbalisation emotional sound Laughter, grieving, stuttering excessive speech Singing, sing-song voice Weeping, Sobbing, lamenting Groaning, moaning, humming, yawning, snoring Shouting, crying out, bossiness
Stores or controls the non-material energies of Conscious-ness; spirit, the will to live, psychic energy Thoughts, ideas, inspirationsopinions, physical energy Life energy (Qi) Animal spirit, vital energy Willpower, ambition Soul, spirit, Spiritual faculties "First cure the spiritthen cure the body",blood, energy
Body flavour, likes or dislikes Bitter Sweet Hot, spicy, pungent Salty Acid, sour as in vinegar
Creates (->) (via Sheng Cycle) Earth
HT -> SP
SI -> ST
SP -> LU
ST -> LI
LU -> KI
LI -> BL
KI -> LV
BL -> GB
LV -> HT
GB -> SI
Destroys (X) (via Ko Cycle) Metal
Governs (via reverse Ko Cycle) Water
Exertion (which weakens) Too much walking Too much sitting Too much lying down Too much standing Too much use of eyes
Body Time 1100-1500h
0700-1100h 0300-0700h 1500-1900h 2300-0300h
Face Colour Red Yellow White Blue-Black Green
Climate (Good/bad) Heat Damp, Humidity,Late Summer Dryness Cold Wind
Season Summer Late Summer Autumn Winter Spring
Growth/development Growth Transformation Reaping Storing Germination
Direction South Centre West North East
Dreams Fires,blazes, looking for fire; fear & laughter hills; mountains towns, streets Hunger,no food/drink, buildings walls and houses, playing music; chanting; ruined buildings; body heavy; can't rise; hills; marshes; storms White objects, cruel; killing of people crying; flying in the air; strange metal objects; fields; country-side; landscape, frightful dreams Water, drowning, ships; fright; fears; back & waist feeling open & split apart, ravines walking & excursions Being trapped, mushrooms; lying under tree ; afraidto get up; trees in mountain forest; battles & fight; cutting open one's body
Meat Mutton, lamb dog Beef Horse Pork, fish Fowl,chicken
Vegetable Coarse greens scallions onions leeks mallows
Fruit Plum apricot chestnut dates peaches
Grain Millet millet,rye rice beans, peas, wheat
Note Chih Kung Shang Yu Chio
Number 7 3 9 6 8

In the Ko Cycle, there are two types of Qi transfer (a) Therapeutic Qi transfer and (b) Pathological Qi transfer.

Ko Cycle Fire X Metal X Wood X Earth X Water X Fire
Yang to Yang transfer SI X LI X GB X ST X HT X SI
Yin to Yin transfer HT X LU X LV X SP X KI X HT

The distinction between pathological transfer of Qi (Yin -> Yin; Yang -> Yang) and the therapeutic transfer (Yin -> Yang; Yang -> Yin) is most important in diagnosis and therapy.

In the Five Phase Cycle the term Heart, HT etc refers not only to the heart organ but to all attributes of HEART (i.e.) Function, COS and Correspondences. This principle is applied to all COSs. Thus, when a master acupuncturist diagnoses a Deficiency in HT or Excess in LI, it does not necessarily mean physical weakness of the heart organ or hyperactivity of the colon organ. Rather, it means that the functions of HT are Deficient or that the functions of LI are Excessive. (There may be physical changes in the respective organs also). If the condition is not treated, physical changes will almost certainly occur in due course.