SP-04 (Gong Sun) Yellow Emperor

What does SP-04 Gong Sun do?

Gong Sun SP-04 carries two classifications and both are load-bearing: it is the Luo (Connecting) point of the Spleen Channel of Foot Tai Yin, and it is one of the eight Confluent points — the point that opens the Penetrating Vessel (Chong Mai), in partnership with P-06 Nei Guan. The Connecting classification gives it the digestive middle; the Confluent classification gives it the Chong Mai, described in the classics as the Sea of Blood and the Sea of the Twelve Channels, rising from the lower abdomen through the chest. That is why one small point on the arch of the foot is recorded for stomach pain, for menstrual disorders and for oppression in the chest at the same time.

• Fortifies the Spleen and harmonises the middle jiao — the Luo-point action and the foundation of everything else. Recorded for epigastric pain, vomiting, poor appetite, distension after eating, borborygmus and loose stools.
• Regulates qi and resolves dampness — for abdominal fullness, heaviness, diarrhoea and dysenteric disorders, the classic Spleen-damp picture.
• Regulates the Penetrating Vessel — the Confluent-point action. The Chong Mai is the vessel of blood and of the uterus, and this is the recorded basis for the point's use in irregular or painful menstruation, in bleeding disorders, and in the surging, rising sensation from the lower abdomen to the chest that the classics call "running piglet".
• Benefits the Heart and chest — the reach of its Confluent pairing. The Chong Mai and the Yin Linking Vessel between them command the heart, the chest and the stomach, which is the territory the SP-04 and P-06 pair is used for.
• Calms the spirit — recorded for restlessness, insomnia and mania, understood in the tradition as an extension of settling the chest and the middle rather than as an independent spirit action.

The unifying idea is a vertical one. The Spleen governs the middle; the Chong Mai runs upward from the lower abdomen through the middle to the chest. Gong Sun is where the tradition reaches that whole vertical line from below.

Source: Sacred Lotus sources & references (channel, Luo-Connecting and Penetrating Vessel Confluent classification, existing action record); Deadman & Al-Khafaji, A Manual of Acupuncture, p. 186; Chinese Acupuncture & Moxibustion, p. 158; Luo-point scheme per Ling Shu (Spiritual Pivot), Chapter 10; cross-referenced against multiple online sources.

What is SP-04 Gong Sun used for?

Gong Sun SP-04 is used above all for the stomach and abdomen — pain, distension, vomiting and disordered stools — and secondarily for the chest and for menstrual disorders through its Penetrating Vessel connection. The indications carried in Sacred Lotus sources & references are gastric pain, vomiting, abdominal pain and distension, diarrhoea, dysentery and borborygmus; the wider reference literature sets the list out as below. These describe traditional use, not proven treatment.

• Epigastric and gastric pain
• Vomiting, nausea and belching
• Abdominal pain and distension
• Borborygmus (rumbling of the intestines)
• Diarrhoea and dysenteric disorders
• Undigested food in the stool
• Poor appetite and fullness after eating
• Oedema and a sensation of heaviness in the body
• Pain and oppression in the chest; pain below the heart
• Irregular menstruation and painful periods
• Uterine bleeding
• "Running piglet" — a surging sensation rising from the lower abdomen to the chest
• Restlessness, agitation and insomnia
• Pain and swelling along the inner border of the foot

Source: Sacred Lotus sources & references (existing indication record); Chinese Acupuncture & Moxibustion, p. 158; Deadman & Al-Khafaji, A Manual of Acupuncture, p. 186.

Where is SP-04 Gong Sun, and how is it used in practice?

Gong Sun sits on the inner border of the foot, in the hollow just in front of and below the base of the first metatarsal bone — the long bone of the big toe — at the junction of the red and white skin where the sole meets the instep. The way it is found is to run a finger backward along the inner edge of the foot from the big toe until it drops off the end of that bone into a depression. It lies on the arch, a little way behind SP-03 Tai Bai, the Source point, and well in front of SP-05 Shang Qiu at the ankle. The "junction of the red and white skin" is the boundary between the paler skin of the sole and the darker skin of the instep, and it is one of the tradition's most practical location devices.

Which points is SP-04 combined with?

• With P-06 Nei Guan — the confluent pair, and the most-used of the four. SP-04 opens the Penetrating Vessel from the foot, P-06 opens the Yin Linking Vessel from the arm, and together they command the heart, the chest and the stomach. Both points are held here, and unusually both are also Luo-Connecting points, which gives the pair a double reach that the other three couples do not have. There is documentary evidence for its pre-eminence rather than just assertion: an analysis of 2,243 items of ancient acupuncture literature on chronic gastritis found that, among all the special-point combinations recorded, the pairing of P-06 and SP-04 showed the strongest association of any (PMID 32959601).
• With ST-36 Zu San Li and REN-12 Zhong Wan — the standard trio for epigastric pain and vomiting, joining the Spleen's Connecting point to the Stomach's He-Sea point and the Front-Mu point of the stomach. A data-mining study of ancient prescriptions for epigastric pain ranked the most frequently used points as REN-12 Zhong Wan, REN-13 Shang Wan, ST-36 Zu San Li, P-06 Nei Guan and SP-04 Gong Sun (PMID 39943771).
• With SP-03 Tai Bai — the Spleen channel's own Source point, two finger-widths away on the same edge of the foot. Source-and-Connecting pairing within a single channel is used where the Spleen itself is the target rather than the Chong Mai.
• With ST-40 Feng Long — the Stomach channel's Connecting point. The Source-and-Connecting pairing across a coupled pair of channels is a classical structure; here Spleen and Stomach are treated as a unit.
• With SP-06 San Yin Jiao and REN-04 Guan Yuan — for the menstrual and lower-abdominal indications that follow from the Penetrating Vessel connection.
• With ST-25 Tian Shu — for diarrhoea and abdominal pain, joining the distal point to the Front-Mu point of the Large Intestine on the abdomen.
• Method — Sacred Lotus sources & references record moxibustion as applicable at this point.

What are the eight Confluent points, and which does this site hold?

Sacred Lotus sources & references hold all eight Confluent points of the extraordinary vessels, in their four traditional pairs, and SP-04 is the point that opens the Penetrating Vessel. The eight Confluent points (ba mai jiao hui xue) are the points on the ordinary channels at which the eight extraordinary vessels can be reached and opened. Each is paired with one other — always one point on the arm and one on the leg — and each pair commands a defined region of the body:

• P-06 Nei Guan (Yin Linking Vessel) with SP-04 Gong Sun (Penetrating Vessel) — the heart, the chest and the stomach. This pair.
• SI-03 Hou Xi (Governing Vessel) with BL-62 Shen Mai (Yang Motility Vessel) — the inner corner of the eye, the neck and occiput, the ear, the shoulder, the spine and the back.
• SJ-05 Wai Guan (Yang Linking Vessel) with GB-41 Zu Lin Qi (Girdling Vessel) — the outer corner of the eye, the cheek, behind the ear, the neck and the shoulder.
• LU-07 Lie Que (Conception Vessel) with KI-06 Zhao Hai (Yin Motility Vessel) — the throat, the chest, the lung and the diaphragm.

Four of the eight — LU-07, P-06, SJ-05 and SP-04 — are Connecting (Luo) points as well and so appear on two classification lists at once; KI-06, BL-62, SI-03 and GB-41 are not. The system was set out in Dou Hanqing's Zhen Jing Zhi Nan in the Yuan dynasty and later elaborated into the Ling Gui Ba Fa, the Mystical Turtle Eight Methods, in which the eight points are opened according to the day and hour of treatment. That framework remains in clinical use: a case report of oculomotor nerve palsy describes a treatment built on the Ling Gui Ba Fa opening of all eight — Wai Guan, Zu Lin Qi, Gong Sun, Nei Guan, Zhao Hai, Lie Que, Shen Mai and Hou Xi — with local and distal points added (PMID 41558712). A single case report proves nothing about outcome; it shows the framework in current use.

Why is SP-04 with P-06 the pair practitioners actually use?

Three reasons, and they compound. First, the territory. The heart, chest and stomach cover a very large share of what walks through a clinic door — nausea, reflux, epigastric pain, chest oppression, palpitations, anxiety felt in the chest — where the neck-and-spine territory of SI-03 with BL-62 or the head-and-flank territory of SJ-05 with GB-41 are narrower. Second, the double classification. Both points are also Connecting points of their own channels, so the pair works simultaneously as an extraordinary-vessel opening and as an ordinary Spleen-and-Pericardium treatment; no other confluent couple has that. Third, the partner. P-06 is the most researched single point in acupuncture, and its established role in nausea and vomiting keeps the pairing in constant use. There is even a laboratory study that separates the two: in rats with experimental acute myocardial ischaemia, electroacupuncture was applied to P-06 alone, SP-04 alone, and both together, with electrocardiographic and electrogastrographic recording. All three groups improved both cardiac and gastric electrical activity, but P-06 had the better effect on the cardiac measure and SP-04 the better effect on the gastric measure (Wang SB et al., World J Gastroenterol 2008;14(42):6496–502, PMID 19030201, PMC2773335). That is animal work and proves nothing clinically — but it is a rare instance of a study designed around the classical claim that this pair reaches both the chest and the stomach.

Source: Sacred Lotus sources & references (location records, Luo and Confluent classifications, and the full eight-point Confluent set together with the P-06, SP-03, SP-05, SP-06, ST-25, ST-36, ST-40, REN-04 and REN-12 records queried directly); Deadman & Al-Khafaji, A Manual of Acupuncture, p. 186; Chinese Acupuncture & Moxibustion, p. 158; Zhen Jing Zhi Nan (Dou Hanqing, Yuan dynasty); PubMed PMID 32959601, 39943771, 41558712, 19030201 (PMC2773335); cross-referenced against multiple online sources.

Where is SP-04 located?

• A Manual of Acupuncture (p. 186): On the medial side of the foot, in the depression distal and inferior to the base of the first metatarsal bone.
• Chinese Acupuncture and Moxibustion (p. 158): In the depression distal and inferior to the base of the 1st metatarsal bone, at the junction of the red and white skin.

How is SP-04 Gong Sun needled in the textbooks?

Reference record only — this sets out what the standard texts document, not instruction for a reader. Said plainly at the outset: SP-04 is a low-hazard point. Sacred Lotus sources & references record perpendicular insertion of 0.5 to 0.8 inch, with moxibustion applicable. Deadman & Al-Khafaji record a comparable perpendicular range and additionally document oblique insertion directed toward the sole of the foot. There is no body cavity anywhere near this point and no organ beneath it.

• Angle documented: perpendicular into the hollow on the inner border of the foot; oblique insertion toward the sole also recorded.
• Depth documented: approximately 0.5–0.8 cun.
• Moxibustion: documented as applicable.

Safety reference — the measured anatomy. What bounds this point is entirely local and can be stated precisely. Immediately deep to the skin and a thin subcutaneous layer lies the abductor hallucis muscle, the fleshy belly that runs along the inner border of the foot; beneath and behind it is the shaft and base of the first metatarsal bone, which forms the floor. Passing across the region are the insertions of tibialis anterior and tibialis posterior onto the first metatarsal base and the navicular. The medial plantar nerve and artery, branches of the tibial nerve and posterior tibial artery, run deeper and more toward the sole, and the medial marginal vein runs superficially along the inner edge of the foot.

The events recorded at points of this kind are correspondingly local: superficial bruising where the marginal vein is nicked, a transient radiating sensation into the sole or the big toe where a cutaneous branch is contacted, striking periosteum on the metatarsal, which is documented as sharply painful, and ordinary needling soreness in a fleshy muscle. None is in the class of the pneumothorax risk that attends points over the thorax and upper back or the orbital risk that attends the deep eye points. No pregnancy caution is recorded at SP-04 in the standard references — that caution attaches to certain other points, SP-06 San Yin Jiao and LI-04 He Gu among them, and should not be transferred here by assumption. Standard clean-needle practice applies. Acupuncture is carried out only by a qualified, licensed practitioner; this record documents the literature and is not a technique guide.

Source: Sacred Lotus sources & references (existing needling record); Chinese Acupuncture & Moxibustion, p. 158; Deadman & Al-Khafaji, A Manual of Acupuncture, p. 186 (surface and deep anatomy of the medial foot).

What does the name Gong Sun mean?

Gong Sun is one of the most argued-over names in the point vocabulary, and two readings are recorded — our own translation field carries the first of them.

• "Yellow Emperor." Gongsun was the clan name of Huang Di, the legendary Yellow Emperor to whom the Huang Di Nei Jing is attributed. On this reading the name honours him, and commentators connect it to the Yellow Emperor's association with the Earth element and the colour yellow — Earth being the element of the Spleen, the channel this point sits on. That correspondence is why the reading has stuck.
• "Grandfather Grandson." Read literally, gong is a grandfather or venerable elder and sun is a grandson or descendant. This reading describes what a Connecting point does: the main channel is the ancestor, and the connecting branch that departs from it is the descendant. The Ling Shu uses a related generational vocabulary for the branching of the vessels, with the great channels giving rise to connecting vessels and those in turn to the finest superficial ones. On this reading the name is a technical description of the point's category rather than a dedication.

Both are recorded in the reference literature, neither is provably the original, and they are not in conflict — the second explains the category, the first explains the choice of characters. Other renderings encountered include "Grandfather Grandson Vessel" and "Yellow Emperor's Point".

What is the Penetrating Vessel (Chong Mai)?

The Chong Mai — Penetrating Vessel, Thoroughfare Vessel or Surging Vessel — is one of the eight extraordinary vessels and, on the classical account, the deepest and most fundamental of them. Chong means to surge, thrust or penetrate. Three descriptions of it recur, and each has a clinical consequence:

• The Sea of Blood. The Chong Mai is described as the reservoir from which the blood of the whole body, and specifically the menstrual blood, is supplied. This is the basis for SP-04's use in irregular, painful or absent periods and in uterine bleeding.
• The Sea of the Twelve Channels. It is described as the vessel into which all twelve regular channels drain and from which they are replenished — which is why the classics treat it as prior to the ordinary channel system rather than one member of it.
• Its course. The vessel is described as arising in the lower abdomen, emerging at REN-01, ascending with the Kidney channel through the abdomen, dispersing in the chest and continuing to the throat and face, with a descending branch to the leg. That upward course through the abdomen and chest is the explanation the tradition gives for the "running piglet" sensation — a surging that rises from below the navel to the chest and throat — and for SP-04's reach into the chest from a point on the foot.

Modern research has taken the classical framing seriously enough to design experiments around it. A laboratory study applied electroacupuncture at SP-04 alone in rats with chemotherapy-induced premature ovarian insufficiency, explicitly framed on the doctrine that "Gong Sun connects the Thoroughfare Vessel", and reported changes in sex hormones, antioxidant markers and follicle counts (Huang SD et al., Zhen Ci Yan Jiu 2025;50(1):41–9, PMID 39961757). It is animal work and mechanistic rather than clinical — but it is a point-specific study, which is more than most points have.

Is there research on SP-04 Gong Sun?

No randomised clinical trial isolates SP-04, and we will not present the literature as though one did. What exists is a documentary literature confirming its classical pairing, a single-point animal literature, and a large body of trials in which it is one point among several.

• Documentary evidence for the P-06 pairing. The analysis of 2,243 items of ancient acupuncture and moxibustion literature on chronic gastritis found the combination of P-06 Nei Guan and SP-04 Gong Sun to show the strongest association of any special-point pairing in that corpus (Zhang PM et al., Zhongguo Zhen Jiu 2020;40(9):1018–23, PMID 32959601). A separate data-mining study of ancient prescriptions for epigastric pain placed Gong Sun fifth in overall frequency, behind REN-12, REN-13, ST-36 and P-06 (PMID 39943771). These document what practitioners did, not whether it worked.
• Point-specific animal work. The premature-ovarian-insufficiency study above (PMID 39961757), and the acute myocardial ischaemia study that compared P-06, SP-04 and the pair (PMID 19030201, PMC2773335), are the two studies we could locate that treat SP-04 as a variable in its own right.
• Prescription analyses in nausea and vomiting. A complex-network analysis of 489 eligible publications on chemotherapy-induced nausea and vomiting found ST-36 and P-06 to be the commonest combination overall, with Gong Sun named among the principal distal points used (Guo Y et al., Support Care Cancer 2024;32(1):78, PMID 38170261). SP-04 is a supporting point in that literature, not the point tested.

For a point of this kind that is the honest state of the evidence: a very strong classical and documentary record, a thin experimental one, and no trial that isolates it. None of this supports a claim that SP-04 treats gastritis, nausea or menstrual disorders.

How does SP-04 differ from the points near it?

SP-03 Tai Bai lies just in front of it on the same border of the foot, behind the ball of the big toe, and is the Spleen channel's Yuan-Source and Shu-Stream point as well as its Earth point — the point of choice when the Spleen itself is deficient, where SP-04 is the point of choice when something needs moving or when the Chong Mai is the target. SP-05 Shang Qiu sits further back at the ankle and is the channel's Jing-River and Metal point. SP-06 San Yin Jiao, three cun above the inner ankle, is the meeting point of the Spleen, Liver and Kidney channels and the far more commonly used point for gynaecological complaints — and unlike SP-04 it carries an explicit pregnancy caution. KI-06 Zhao Hai and KI-03 Tai Xi lie around the inner ankle on the neighbouring channel. Readers looking for the Spleen's Great Connecting point, which is a different thing again, want SP-21 Da Bao on the side of the chest.

Source: Sacred Lotus sources & references (name, channel, Luo and Confluent classifications, and the SP-03, SP-05, SP-06, SP-21, P-06, KI-03 and KI-06 records queried directly); Deadman & Al-Khafaji, A Manual of Acupuncture, p. 186; Chinese Acupuncture & Moxibustion, p. 158; Ling Shu (Spiritual Pivot), Chapter 10, on the Connecting vessels; Zhen Jing Zhi Nan (Dou Hanqing) for the Confluent-point system; PubMed PMID 32959601, 39943771, 39961757, 19030201, 38170261, 41558712 — each verified resolvable and checked for retraction status before citation; cross-referenced against multiple online sources.