三間 Sanjian
“Third Space” · LI3
Hand Yangming · 3 of 20 · shu-stream
Where. Make a loose fist: on the thumb side of the index finger, in the hollow just behind the big knuckle.
For. Toothache, sore throat, puffy, aching fingers.
Press. Fingertip pressure toward the bone, about a minute each hand.
三間者，木也。一名少谷，在手大指次指本節後內側陷者中按 · Press with me
Six slow breaths
About a minute. Press as you breathe out, ease as you breathe in.
鄰 · Neighbouring leaves
Where Sanjian Sits on the Index Finger
The dataset locates Sanjian with the fist slightly clenched, on the radial side of the index finger, in the depression proximal to the second metacarpophalangeal joint, at the junction of the red and white skin. Each phrase unpacks cleanly. Radial means the edge of the index finger that faces the thumb, named for the radius, the forearm bone on that side. Proximal means nearer the trunk — so the depression sought here lies behind the knuckle, toward the wrist, not in front of it. And the second metacarpophalangeal joint is less formidable than it sounds: the second metacarpal is the long bone inside the index finger, so its meeting with the finger bone is simply the big knuckle at the base of the index.
The junction of the red and white skin is a traditional landmark worth knowing in its own right. Along the side of the finger, palmar skin — paler, hairless, creased for gripping — hands over to the finer, often darker skin of the back of the hand, and the boundary draws a visible line. Classical location practice used this colour border as a ruler all along the fingers, and it appears in the records for the channel’s first points alike. Behind the index knuckle, on the thumb side, the line runs through soft ground: the tendons that straighten the finger spread flat here, and between them the flesh parts enough to leave a genuine hollow under a resting fingertip.
Neighbours give the clearest orientation. One space toward the fingertip, on the far side of the same knuckle, sits Erjian (LI2), whose record places it distal to the joint — the mirror image of Sanjian. Farther back, in the web between the bones of thumb and index, lies Hegu (LI4). Sanjian owns the middle ground: the pocket immediately behind the index knuckle, thumb side, where the colour line crosses it. Which side of the knuckle your fingertip rests on decides which of these points you are actually touching, so the distinction is not pedantry — it is the whole difference between arriving and nearly arriving.
A Self-Palpation Walkthrough
Sit comfortably and lay the back of your left hand on a table or thigh, fingers loosely curled into a half fist — the slight clench the dataset asks for. With your right thumb, find the big knuckle of the left index finger and trace to the bump’s thumb-facing edge. From there, walk a thumb-width toward the wrist, staying on the side of the hand, until your pad settles into a shallow dip just where the paler palm-side skin changes to the darker back-of-hand skin. Press feather-light and bend the index finger slowly: the hollow deepens as the knuckle folds, confirming you are in the pocket behind it. Repeat the whole search on the other hand.
Two checks help before any real pressure begins. First, the roll test: extending and flexing the finger should make the knuckle glide under your pad while the spot itself stays put — if the tender-feeling point rides away with the bone, you were sitting on the knuckle itself, a few millimetres off. Second, the comparison test: light contact at the true hollow usually brings a faint, dull awareness, while the skin just beside it stays quiet. What you should not feel yet is anything sharp; if light touch alone stings, move off and try the mirror position a fraction closer to the wrist.
The classic slips are three. Landing on the far side of the knuckle puts you on Erjian instead — easy to do, since both hollows hug the same joint. Sitting squarely on top of the bony knob finds no point at all, only a bruise waiting to happen. And drifting backward into the fleshy web between thumb and index wanders into Hegu’s neighbourhood, losing the knuckle landmark entirely. When in doubt, reset: clench lightly, find the knuckle bump, name its thumb side, then step one hollow behind it. The channel’s own counting helps here — first space at the nail corner, second in front of the knuckle, third behind.
Reading the Name: Third Space
The name is a map reference. San 三 is three; jian 間 means a space, gap, or interval — the word also serves for rooms between walls and pauses between events. Read along the finger, the channel meets a series of small spaces on its way up from the nail: the corner of the nail where Shangyang (LI1) begins, the hollow in front of the index knuckle claimed by Erjian — er 二, two — and the pocket behind that knuckle, which falls to number three. Sanjian is thus the third space, and the two characters double as walking directions for anyone climbing the channel’s first stretch.
The second character rewards a longer look. In earlier forms of the script, jian drew a door with a sliver of light slipping through its seam — an image so literal that the character came to mean gap, interval, separation, and even a moment in time. The modern simplified form keeps the door and brightens the sliver into daylight, but the sense of a thin opening survived intact. Spoken aloud, the name is Sānjiān, a flat first tone on both syllables, easy to say and easier to remember once the picture is in mind. Like gates, valleys, courtyards, and storehouses elsewhere on the channels, it is architecture doing instructional work.
Classical commentators, working centuries apart, read the name the same two ways at once: an ordinal — third point of the channel — and a description of terrain, the gap where flesh yields behind the knuckle. Both readings survive in the dataset this site licenses, and both serve the visitor. The ordinal tells you where you stand in the sequence; the terrain tells your fingertip where to stop. A name that functions simultaneously as address and instruction is the tradition’s quiet genius, and Sanjian is one of its cleanest examples.
A Stream Point on the Hand Yangming Channel
Beyond its place in the count, Sanjian holds a formal title in classical theory: it is the stream point — the shu point — of the large intestine channel. The five transport points sort each channel’s first five locations into an ascending series borrowed from landscape: well, spring, stream, river, and sea. Qi, in the traditional picture, behaves like water — emerging barely at the fingertip wells, trickling at the springs, broadening where the streams run, gathering current at the rivers, and pooling wide at the seas near elbow and knee. Sanjian’s recorded category, shu-stream, sets it at the widening middle of that journey.
Tradition attached a temperament to each stage. Classical teaching describes stream points as places where the flow has gathered body enough to matter, and generalised classical guidance reached for them when complaints felt heavy, settled deep, or came and went with time. That old association lends context to an otherwise curious item on Sanjian’s record: drowsiness. A point class linked with heaviness and dullness carrying an entry for dullness of the waking mind fits the period’s way of thinking — the tradition reasoning from category to use, in its own idiom, long before modern categories existed.
One refinement completes the picture. On the yin channels of the arms and legs, the stream point doubles as the source point, the place where an organ’s own qi is said to pool. On yang channels — and the large intestine runs along the hand’s outer aspect as the hand yangming — the source office moves one station along: Hegu (LI4) holds it here. Neighbouring points therefore share a stretch of hand but hold different offices, which is why classical discussions so often name them together. The channel itself pairs inwardly with the lung channel in the interior–exterior scheme, and both belong to the metal phase in five-phase thought — context the old writers took for granted.
Traditional Indications, Explained
The licensed record lists six indications: toothache, sore swollen throat, abdominal distension, borborygmus, drowsiness, and swollen painful fingers. Laid out plainly, that is a curious portfolio — teeth and throat at one end, guts and sleepiness in the middle, a sore finger at the other. Read inside the tradition, however, each entry has its seat. Framed throughout as what classical practice reached for rather than as promised results, these entries describe how the old system reasoned: from channel course, from organ partnership, from point class, and from sheer locality.
The face entries ride the channel map. The yangming channels sweep across the jaw, mouth, gums, and nose, and the hand yangming finishes its climb beside the nostril; toothache and the sore swollen throat that fills the records of LI1, LI2, and LI3 alike belong to that facial territory. The belly entries ride the organ link: this being the large intestine’s own channel, fullness and wind in the bowel — distension, and borborygmus, the audible gurgling of gas and fluid on the move — were read as the organ’s traffic sounding at a channel window. Drowsiness reflects stream-point temperament, discussed above. And swollen painful fingers is the tradition’s plainest rule at work: the nearest good point serves the nearest complaint.
Honesty requires the other half of the paragraph. These are traditional uses, recorded for cultural and historical understanding; they are not claims that pressing Sanjian treats disease. Where modern research has examined self-applied pressure at all, reviews suggest effects are modest and dependent on context, and evidence tied to any single point remains thin. Practical routing matters more than hope: a toothache is a reason to see a dentist, promptly if swelling or fever joins it. A sore throat with trouble swallowing or breathing, spreading swelling of the neck, drooling, or high fever is an emergency, not a self-care project. Persistent symptoms of any kind belong with a licensed practitioner, medical or East Asian medical as suits the complaint.
Self-Care Acupressure at Home
With the point confirmed, set up gently. Sit upright, rest the back of the hand on your leg, and let the fingers curl easily. Place the pad of your opposite thumb — pads, never tips, nails, or tools — on the hollow and simply rest there through three slow breaths. Then add small circles, letting the skin travel lightly over the tissue beneath. Pressure should register as pleasant dullness or faint warmth, nothing sharper. A common home rhythm is one to two minutes per side, once or twice daily, timed to unhurried exhales. Finish by repeating everything on the other hand, keeping the sessions symmetrical.
Hand points tempt people toward too much force. The skin is thin, the bone close, and a thumb naturally leans hard on such compact ground — so aim deliberately lighter than feels decisive. Warm your hands first on cold days, because chilled tissue guards itself. Give the practice a quiet setting rather than a screen, and let it double as a pause: contact on the inhale, gentle circling on the long way out. People who keep such routines attach them to existing habits — coffee brewing, an afternoon stretch — because regularity, not intensity, is what self-care traditions actually ask of anyone.
Keep expectations sized to the practice. Across a week or two you may notice the area feeling less guarded, or simply enjoy ninety seconds of attended stillness in a busy day; either outcome sits inside acupressure’s honest scope. What sits outside it is escalation — pressing harder, longer, or deeper to force a result, especially over a knuckle that aches afterwards. Soreness that outlasts the session is feedback, and the right response is less, not more. Curiosity that pulls toward force is the signal to return to gentleness or close the day’s practice altogether.
Cautions and Safe Practice
Reassuring geography first: nothing vital lies beneath this spot. Under the skin sit tendon, the small muscles between the knuckles, bone, and the fine nerves and vessels of the finger’s edge — no organs, no cavities — which places hand points among the calmer locations for surface work. The licensed dataset records no specific cautions for Sanjian, and this page echoes that empty record faithfully. An absence of recorded cautions is not an invitation to enthusiasm, though; fingers work hard, meet the world constantly, and deserve a conservative margin all their own.
Practical limits follow. Skip the point whenever the skin there is broken, peeling, bitten, or inflamed — hangnails, cuts, eczema flares, and fungal trouble around the nails all qualify. Set the practice aside after any recent injury to that hand or finger: sprains, jams, fractures under healing, tendon trouble, or an arthritis flare in the knuckle itself. Redness, warmth, or swelling around the joint calls for assessment, not compression. Sharp, electric, or radiating sensation ends the session immediately, that day. Anyone pregnant, and anyone managing chronic illness or blood-thinning medication, does well to consult a qualified practitioner before adding any new point routine at all.
And the frame around everything: this page is educational. Acupressure is comfort self-care — not diagnosis, not treatment, and never a substitute for the professionals whose job is precisely the symptom you may be hoping to quiet. Of the recorded indications, the sore swollen throat carries the sharpest edges: difficulty swallowing or breathing, a muffled voice, drooling, spreading neck swelling, or high fever belongs in urgent medical care today, not in a pressure routine. Toothache with facial swelling or fever belongs with a dentist promptly. Everything slower — a grumbling belly, an achy knuckle-week — can begin, sensibly, with gentleness.
Sanjian, the Third Space, waits on the thumb side of the index knuckle in a shallow hollow just behind it. The large intestine channel’s third point, classical practice reached for it amid toothache, sore swollen throat, or a rumbling, bloated belly. This guide walks through finding it by touch and pressing it gently.
Self-care limits
Frequently asked
- How is Sanjian different from Hegu (LI4), its famous neighbour?
- They share a stretch of hand but hold different posts. Hegu sits further back, between the two metacarpal bones of the thumb–index web, and in classical theory serves as the channel’s source point; Sanjian sits forward, in the pocket directly behind the index knuckle, holding the stream-point post. Classical records list overlapping interests for both, but this guide concerns only gentle self-palpation and surface pressure at Sanjian — locating it correctly is the skill this page teaches.
- I have a toothache right now — should I press Sanjian?
- Book the dental appointment first. A toothache is a symptom asking for assessment, particularly with swelling, fever, or pain that has lasted more than a day or two. Gentle pressure at a classical point may sit alongside ordinary comforts, but it is not a substitute for care, and escalating pressure to chase relief risks a bruised hand on top of an unresolved tooth. The traditional record describes what practitioners of another era reached for, not what replaces modern dentistry.
- Why would a point on the hand carry belly indications in the old records?
- Channel logic. In the classical map, the large intestine channel begins at the index finger and travels inward to connect with its own organ, so the surface route was treated as a live wire between hand and gut. Abdominal distension and borborygmus appearing at a hand point expresses that correspondence, not an anatomical discovery. It is a coherent framework within its own era’s physiology — presented here for understanding the record, not as a claim about outcomes.
- Is Sanjian safe to use during pregnancy?
- Prudence first: check with a qualified practitioner before adding any new point practice while pregnant. Notably, the neighbouring point Hegu (LI4) carries an explicit recorded caution in the licensed dataset about use during pregnancy, and professional guidance covering the whole channel is the sensible course. Sanjian’s own record says nothing specific about pregnancy — which is exactly why an individual answer should come from someone who can see the whole picture, not from a general page.
- How soon should I expect to feel something?
- Expect little and stay patient. Many people notice a faint dull awareness at the point immediately and nothing else for weeks; a few feel warmth spread into the finger. None of that predicts outcomes, and no timetable would be honest. If your purpose is symptom relief and nothing changes over a reasonable stretch, take that as information and bring it to a licensed practitioner. The steadier returns of the practice — a daily pause, a hand attended to — arrive regardless.
Sources
- 01WHO Standard Acupuncture Point Locations in the Western Pacific Region (2008), World Health Organization — nomenclature conventions.
- 02A Manual of Acupuncture, Peter Deadman, Mazin Al-Khafaji and Kevin Baker — point-name tradition, stream-point theory, and channel context.
- 03aijiu-mpvue (MIT License) licensed dataset, entry for LI3 Sanjian — location, point class, actions, and the (empty) caution record.
Last reviewed
牌記This leaf, for machines
Old books ended with a colophon saying who printed them. Every leaf here carries the same facts as structured data for agents and search, with no layout in the way.
- GET /en/points/li3/leaf.json
- GET /zh-hant/points/li3/leaf.json
- GET /zh-cn/points/li3/leaf.json
- /llms.txt — the index of every leaf
- JSON-LD in the page: MedicalWebPage, MedicalEntity and FAQPage
{
"id": "LI3",
"name": {
"en": "Sanjian",
"gloss": "Third Space",
"zh-Hant": "三間",
"zh-Hans": "三间"
},
"channel": {
"id": "LI",
"order": 3,
"of": 20
},
"location": {
"text": "Make a loose fist: on the thumb side of the index finger, in the hollow just behind the big knuckle."
},
"for": [
"toothache",
"sore throat",
"puffy",
"aching fingers"
],
"press": {
"text": "Fingertip pressure toward the bone, about a minute each hand.",
"seconds": 60,
"sides": "both"
},
"cautions": [],
"source": "Zhenjiu Jiayi Jing, book 3",
"url": "https://acupoints.com/en/points/li3",
"lastReviewed": "2026-08-24"
}