This article is part of a series explaining the body’s organ systems from the perspective of Traditional Chinese Medicine (TCM) and Five Elements Theory.
According to Traditional Chinese Medicine (TCM), the Heart and Small Intestine are related to the Season of Summer.
TCM, the Five Elements and Summer
The Five Elements (Water, Fire, Wood, Metal, Earth) are qualities of nature that are foundational to the theory of TCM. The theory of the Five Elements is systematically applied to symptomatology, diagnosis, and treatment. Some may argue that, together with the theory of Yin-Yang, it constitutes the foundation of TCM theory.
Each season is associated with an element, organ system, taste, etc. Each of these correspondences are then utilized in identifying patterns (TCM diagnosis), and treatment options. For example: Herbs that are recommended for phlegm in the sinuses are generally pungent (acrid).
A partial list of the Five-Elements correspondences for Summer includes:
- Season — Summer
- Element — Fire
- Yin Organ system — Heart
- Yang Organ system — Small Intestine
- Developments — Growth
- Color — Red
- Sounds —Laughing
- Emotions — Joy
- Taste — Bitter
- Tissue — Blood vessels
- Sense organ — Tongue
- Climate — Heat
The Heart has seven principal functions
- Governs the blood
- Controls the blood vessels
- Manifests in complexion
- Houses the mind (shen)
- Connects to joy
- Opens into the tongue
- Controls sweat
The Heart, according to TCM, is often referred to as the “emperor” or “monarch” of all other organs. This can even be seen in its physiological function of pumping blood to all parts of the body. Once the heart stops, blood stops flowing, and death is imminent.
Summer and the Heart
The Heart likes heat. The warmth of summer fire – through temperature, exercise and joy – encourages the invigorating movement of blood through the vessels. Cold weather creates the opposite effect on the blood.
Heart governs blood
The Heart governs the blood in two ways. The transformation of Food-Qi into blood takes place in the Heart. And, just like in Western medicine, the Heart is responsible for blood circulation. However, in TCM the Lung, Spleen, and Liver also play a role in blood circulation.
When the Heart blood is deficient you see a decrease in circulation and may see cold hands.
The strength and constitution of an individual can also be determined by the relationship of Heart and blood. The primary determining factor when it comes to constitution is related to the Kidney function. If the Heart is strong there is ample blood supply and circulation is good.
The Heart blood directly influences menstruation and fertility. Liver blood primarily controls menstruation, and is stored in the uterus. However, it is the Heart that controls blood discharge (downward movement of Qi and Blood) that occurs during menstruation.
It is said that the Heart “governs” the blood, the Liver “stores” the blood and the Spleen “makes” the blood. All of these organ systems work together in harmony to create the symphony of blood movement throughout our body. When one organ system is having dysfunction it is only a matter of time before all systems are “offline.”
Heart controls the blood vessels
Because the Heart governs the blood it naturally controls the vessels, connecting to the arteries, veins, capillaries and making a complete circuit. The Heart’s energy determines the health of the blood vessels. If Heart Qi is strong the blood vessels will be in a healthy state causing a full and regular pulse. Deficient Heart qi can be seen in a feeble and irregular pulse.
In TCM, “blood vessels” constitute one of five energetic layers, each controlled by a given organ system. These are:
- Skin (Lungs)
- Muscles (Spleen)
- Sinews (Liver)
- Blood vessels (Heart)
- Bones (Kidney)
(Maciocia, 2005, p 108)
The pulse, within TCM, is used as a diagnostic tool. Depth, width, rate, and quality are all taken into consideration. Pulse is taken bilaterally (both sides).
The five energetic layers can be seen as “layers” within the pulse:
- Skin and Muscles (Lung and Spleen) – Superficial levels
- Sinews and Blood (Liver and Heart) – Middle levels
- Bones (Kidney) – Deep levels
Heart manifests in the complexion
The state of the Heart can be seen in the complexion, especially on the face. A healthy complexion may indicate a healthy Heart.
Evidence of dysfunctions found in the complexion:
- Blood deficiency: complexion is pale, dull white
- Heart yang deficiency: bright white complexion
- Heart Blood Stasis: purplish or dull and dark complexion
- Heart heat: complexion is too red (could also indicate Lung or Liver heat)
Heart houses the mind
The Heart houses the mind (shen). The term shen can have many different meanings. However, shen generally refers either to the complex mental faculties which “reside in the Heart,” or to a whole sphere of mental and spiritual aspects of a human being. The latter meaning of shen encompasses the mental and spiritual aspects of ALL the other organ systems.
Spiritual aspects of internal organs
- Liver – Ethereal Soul (Hun) – responsible for sleep, plans, projects, life aims, ‘coming and going of Shen’
- Lung – Corporeal Soul (Po) – responsible for physiological activities, sensations, sight, hearing,smell, taste, ‘entering and exiting of Jing’
- Spleen – Intellect (Yi) – responsible for thinking, memory, concentration
- Kidney – Will-power (Zhi) – responsible for will-power, drive, determination
- Heart – Mind (Shen) – responsible for consciousness, thinking, affections, memory, sleep
Heart opens into the tongue
The tongue is considered an “offshoot” of the Heart. You will also see this in the channel pathway (below).
The tongue is used in TCM diagnostics
The Heart controls the color, form and appearance of the tongue. Pathologies of the Heart are frequently seen on the tip of the tongue.
- Normal tongue: normal pale-red color
- Heart heat: dry and dark red, tip may be redder and swollen. Client may have a bitter taste in their mouth
- Severe heat: may have tongue ulcers that are red and painful
- Heart deficiency/Heart blood deficiency: pale and thin tongue
- Heart excess or deficiency: excessive talking, difficult speech, stuttering, aphasia
If the Heart qi is healthy a person should be able to distinguish all 5 tastes.
Note: A long thin crack down the midline of the tongue could indicate a weak Heart constitution and a tendency towards emotional problems.
Heart controls sweat
When you work out your heart rate increases and you start to sweat. According to TCM, sweat and blood have a common origin. Sweat, one of the body’s “fluids,” comes from the space in between the skin and muscles. Because Heart governs blood and its fluid is sweat there is an interchange that takes place. Dysfunction can be seen when “blood” is too thick or too thin.
- Heart deficiency of Qi or Yang: spontaneous sweating
- Heart yin deficiency: night sweats (also seen with Kidney yin deficiency)
- Excessive sweating in hot weather, hot yoga, etc may damage the Heart yang
Note: Excessive sweating could also be due to the Lung qi, damp heat, heat- especially from the Stomach.
The Heart and Small Intestine Organ Systems
The Heart is considered to be the internal, yin organ system. It forms a pair with the Small Intestine, which is considered to be the external, yang organ system. You can find the relationship between the Heart (HT) and Small Intestine (SI) in how the energy flows through the meridians or channels. Note the internal connection between the meridians, and where the last point of the Heart meridian begins to where the Small Intestine Meridian begins. For a more detailed description please read pp. 209-248 of A Manual of Acupuncture. 
Note: “Cun” is a TCM form of measurement. One cun is equivalent with the width of the interphalangeal joint (the top part of your thumb). A cun is based on your client’s body measurement.
The Heart Channel of Hand Shaoyin
The Primary Channel of the Heart
- Originates in the Heart
- Emerges from the system of blood vessels surrounding the Heart and descends through the diaphragm to connect with the Small Intestines
- A branch separates from the Heart, ascends alongside the oesophagus and then across the face and cheek to connect with the tissues surrounding the eye
- Another branch travels directly from the Heart to the Lung and descends to emerge from the axilla (armpit) at acupuncture point HT 1
- Then travels along the medial aspect of the upper arm (medial to the Pericardium and Lung channels) to the medial elbow at HT 3
- Descends along the antero-medial aspect of the lower arm to the pisiform bone of the wrist at HT 7 (Shen men: Shen meaning mind, this point calms the mind)
- It then travels through the palm and along the radial side of the little finger to terminate at the radial corner of the nail at HT 9- Where it then connects with the SI channel
(Deadman et al., 2005, p 209)
The Small Intestine Channel of Hand TaiYang
The Primary Channel of the Small Intestine
- Originates at the ulnar side of the tip of the little finger at SI 1
- Ascends along the ulnar aspect of the hand to reach the wrist where it emerges at the styloid process of the ulna at SI 6
- Follows the ulna to the medial aspect of the elbow, where it passes between the olecranon of the ulna and the medial epicondyle (your “funny bone”) of the humerus at SI 8
- Runs along the posterior aspect of the upper arm (intersecting with the Large Intestine Channel at LI 14- at the shoulder) to the posterior aspect of the shoulder joint at SI 10.
- It then zig-zags from the inferior fossa to the superior fossa of the scapula through SI 11 and SI 12, and then to the medial aspect of the scapular spin at SI 13
- It Crosses via SI 14 and SI 15 to DU 14 (aka Governing Vessel – GV 14), at the lower border of the spinous process of C7 (cervical vertebra – at the base of the neck), intersecting with the Bladder channel (BL) at BL 41 and BL 11
- Descends along the esophagus, intersects the Conception Vessel (aka Ren) at REN 13 and REN 12 (on the midline of the abdomen) and enters the Small Intestine
Branch One of the Small Intestine Channel
- Ascends from the supraclavicular fossa (near the “base of the throat”) to cross the neck and cheek to the outer canthus of the eye, where it meets the Gallbladder (GB) channel at GB 1, then travels posteriorly towards the ear, where it intersects at GB 11 and the SanJiao channel (SJ) at SJ 20 and SJ 22. Then enters the ear at SI 19 (located on the tragus of the ear)
Branch Two of the Small Intestine Channel
- Separates from the previous branch on the cheek and ascends to the infra-orbital region SI 8 (located in line with the outer edge of the eye “outer canthus” in the depression below the cheek bone “zygomatic arch”) then along the lateral aspect of the nose to the inner canthus where it meets the Bladder (BL) channel at BL 1
- According to some sources, another branch descends to ST 39 (Stomach 39) the Lower He-sea point of the Small Intestines.
(Deadman et al., 2005, pp 227-228)
- Eating for the season: Summer
- Emotional aspects of the Heart according to TCM
- Summer Salad Recipes
- Summer Soup Recipe
- Deadman, P., Al-Khafaji, M., & Baker. K. (2005). A Manual of Acupuncture. East Sussex: Journal of Chinese Medicine Publications.
- Hyunbae,K. (2007). Handbook of Oriental Medicine (3rd ed.). Harmony & Balance Press.
- Kastner, J. (2004). Chinese Nutritional Therapy. Jeorg Thieme Verlag.
- Maciocia, G., & Xin Ming, S. (2005). The Foundations of Chinese Medicine: A Comprehensive Text for Acupuncturists and Herbalists. London: Churchill Livingstone.
- Pitchford, P. (2002). Healing with Whole Foods (3rd ed.). Berkeley, CA: North Atlantic Books.
- Wiseman, N. (ed., trans.), & Ellis, A. (trans.) (1996). Fundamentals of Chinese Medicine. (Rev. ed.) Brookline, MA: Paradigm Publications.