二間 Erjian
“Second Space” · LI2
Hand Yangming · 2 of 20 · ying-spring
Where. Make a loose fist: on the thumb side of the index finger, just in front of the big knuckle, where palm skin meets back skin.
For. Toothache, nosebleed, sore eyes.
Press. Fingertip pressure into the hollow, about a minute each hand.
二間者，水也。一名間谷，在手大指次指本節前內側陷者中按 · Press with me
Six slow breaths
About a minute. Press as you breathe out, ease as you breathe in.
鄰 · Neighbouring leaves
Where Erjian Sits on the Index Finger
With a slight clench of the fist, Erjian appears on the thumb side of the index finger, in the shallow depression just beyond the big knuckle — the second metacarpophalangeal joint, in anatomical language. The dataset adds a poetic-sounding landmark: the junction of the red and white skin, the traditional name for the line where the paler skin of the palm side meets the deeper-toned skin of the back of the hand. Run your gaze along the outer edge of the index finger and you can usually see this boundary yourself, a soft colour shift running lengthwise. Radial side simply means the thumb-facing edge, and distal to the joint means on the fingertip side of it rather than the wrist side. Every word of the classical location therefore maps onto something visible on an ordinary hand.
What lies beneath the skin here asks for a light touch. The depression sits directly over the joint capsule and the flat tendon that straightens the finger, with only thin tissue between them and the surface; small digital nerves and blood vessels travel along both borders of the finger nearby. Fingers are among the most touch-sensitive parts of the body precisely because their wiring is dense and close to the skin — good news for acupressure, since sensation arrives early and little force is ever needed, and equally a reason to abandon any thought of pressing hard on a small joint. The point answers patient contact the way a tuning fork answers a feather: barely any input, plenty of reply.
Neighbors help confirm the address. Counting from the outer corner of the index fingernail along the thumb-facing border, the channel’s first point, Shangyang (LI1), hugs the nail corner; the next substantial hollow before the big knuckle is Erjian; and passing over the crest of the knuckle toward the hand brings you to Sanjian (LI3), whose name — third interval — continues the count. The three form a tidy instructional sequence built into the geography of a single finger segment. Once you can place the knuckle and the hollow in front of it, you hold the map for all three points at once, because the naming scheme itself spells out the order.
A Self-Palpation Walkthrough
Sit comfortably and make a loose half-fist, curling the fingers enough to round the knuckles without squeezing. With the other hand, find the big knuckle at the base of the index finger — the joint where the finger meets the hand proper. Slide your exploring fingertip to the thumb-facing side of that knuckle, then walk it slightly toward the fingertip, over the rounded crest of the joint. Just beyond the crest the ground should fall away into a shallow dip; settle there, and check that the spot lies along the faint colour boundary where palm skin yields to back-of-hand skin. That dip, on that edge, at that boundary, is the whole of the location.
Two quiet confirmations earn their keep. First, compare sides with feather-light taps: many people notice a faint, dull awareness at the true point and almost nothing a few millimeters away. Second, change the finger’s posture — clench a little tighter and the hollow tends to deepen and announce itself, while straightening the finger lets it soften again. If your fingertip rests on a hard ridge instead of a dip, you are probably sitting on the crest of the bone itself; ease off toward the palm side or a touch further toward the fingertip and search again. None of this probing should hurt — discomfort during location usually means too much pressure rather than the wrong place.
Common slips are predictable. Drifting over the top of the knuckle toward the back of the hand lands you nearer Sanjian’s territory, which is the wrong side of the joint for this exercise. Hugging the underside of the finger leaves the colour boundary and strays toward the palm surface. Using a fingernail instead of the pad turns a gentle search into a poke, so trim nails and let the fleshy pad do the work throughout. When confusion wins, release the fist, shake the hand out, re-clench softly, and begin again from the big knuckle; the landmark has never moved.
Reading the Name: Two Intervals
The name reads like coordinates. Er 二 means two, and jian 間 means an interval, gap, or space between things. Counting the gaps along the thumb-facing border of the index finger outward from the nail, this is the second space the channel meets, and the name simply reports the count — the same arithmetic that names its neighbor Sanjian, the third interval. Pinyin writes it ěrjiān, a dipping third tone on er and a level first tone on jian. The two characters 二間 are among the simplest in the whole point atlas, which makes them easy to remember: a number, and a gap.
A second layer of meaning belongs to point classification. Classical teaching organises the points nearest the fingers and toes into five offices per channel, named for water gathering force downhill: a well, a spring, a stream, a river, and a sea. Erjian holds the spring office of the large intestine channel — the stage where the flow, having surfaced at the well, gathers into something lively but still young. Classical five-phase teaching, as carried in standard references such as A Manual of Acupuncture, assigns the spring points of the yang channels to the water phase, and water’s traditional role in that system is to meet and temper heat. It is a lens for reading the tradition, not a laboratory finding.
The imagery repays attention. A spring is cool, quick, and constant — exactly the qualities classical practice liked to reach for when the body ran hot, whether the heat showed as feverishness, a flushed throat, or an angry gum. The old aphorism, paraphrased rather than quoted, taught that spring points answer hot states. Whatever one makes of the physiology, the classification does real explanatory work: it tells you at a glance why a small point on a knuckle spent centuries appearing in discussions of feverish illness alongside toothaches and nosebleeds. The name, once again, doubles as instructions.
Traditional Indications, Explained
The recorded indications read: toothache, nosebleed, febrile disease, eye disorders, and periarthritis of the shoulder. Read traditionally, they hang together. Toothache heads the list because classical texts draw the large intestine channel up the arm and into the face, where it is described as reaching the lower gums and teeth — a point near the channel’s beginning was read as speaking to territory along its route. Nosebleed fits the same logic at the other end of the drawing: the channel is classically described as terminating beside the nostril, so a finger point could be consulted for a nose in trouble.
Febrile disease — the old umbrella term for feverish illness — enters through the classification discussed above, spring points being traditionally associated with hot states. Eye disorders join through the yangming logic of the face: classical practice grouped red, painful, heat-flavored eye complaints with upward-drifting warmth in the channels crossing the face, and reached for distant points on those channels. Periarthritis of the shoulder — the stiff, aching shoulder family the older records knew well — reflects the channel’s own itinerary, which passes the shoulder before arriving at the face; when a road caused trouble, travelers asked at stations along the road. Each entry is traditional reasoning, coherent within its own map.
It bears saying plainly: these are the traditional uses recorded in a licensed dataset and classical literature, offered here for cultural and historical understanding. They are not claims that pressing this point treats any condition, and nothing in this guide substitutes for assessment by a qualified clinician. Where modern research has touched self-applied acupressure at all, reviews suggest effects tend to be modest and dependent on context, and evidence specific to any single point remains sparse. Hold the tradition lightly and the safety rules firmly, and the two will never collide.
Self-Care Acupressure at Home
Settle first: seated, shoulders heavy, the located hand resting palm-down on your thigh. Bring the pad of your opposite thumb or index finger onto the dip, and begin with bare contact — a few unhurried breaths carrying no pressure beyond the weight of the finger itself. Then add small, slow circles, letting the skin glide over the tissue rather than grinding against the joint beneath. Aim for a pleasant dullness, perhaps a mild warmth spreading along the finger edge; any sharpness anywhere in the experience is a cue to lighten or stop. A common home rhythm is one to three minutes per side, once or twice daily, with the pressure riding gently on each exhale. Swap hands and give the other side its turn.
Fingers ask for even less force than body points. Their skin is thin, their nerves sit close to the surface, and their joints are small — so halve whatever pressure feels normal elsewhere, and keep nails short so the pad, not the edge, does the work. Warm hands press more kindly than cold ones; if yours run cold, rub them together before starting. Quality beats duration: two minutes of genuinely light, attentive contact serves the practice better than ten absent-minded ones. Many people anchor the routine to an existing habit — morning coffee, an afternoon pause at the desk — because regularity, not intensity, is what self-care traditions actually request.
Treat the minutes as a small ceremony of attention rather than a treatment session. Across weeks you may notice the area feeling less tender, the hand moving more freely, or simply that you spent ninety seconds attending to your own body — every outcome inside the honest scope of self-acupressure. What falls outside it is escalation: pressing harder, longer, or more sharply to force a result. Curiosity that pulls that way is best answered by returning to gentleness, or by closing the practice for the day. The point has waited centuries already; it can wait until tomorrow.
Cautions and Safe Practice
The licensed dataset records no special cautions for this point, and it is worth stating that plainly — together with what it does not mean. An empty caution column is not an invitation to force. Small joints, thin skin, and nerves traveling just beneath the surface mean this neighborhood rewards exactly the light, purely superficial contact this page recommends everywhere else, and it punishes jabbing. Never press hard onto a bony ridge, never work with a tool or device, and never push sensation beyond pleasant dullness.
Conservative defaults cover the rest. Skip the point entirely over cuts, scrapes, broken or irritated skin, warts, eczema patches, or any inflammation around the nail folds or knuckle; leave it alone while a finger injury, sprain, or recent surgery heals, until ordinary use feels comfortable again or a clinician clears it. Sharp, electric, or radiating sensation means stop at once and do not retry that day. Pregnant readers, and anyone living with a condition that affects the circulation or sensation of the hands — diabetes with neuropathy, Raynaud-type sensitivity, and similar — do best to consult a qualified practitioner before adding any new point practice. When in doubt, ask first; the question costs nothing.
Red flags outrank routines. A toothache with facial swelling, fever, or trouble opening the mouth or swallowing needs urgent dental or medical care today, not a pressing schedule. Recurrent or unusually long nosebleeds — and any nosebleed while taking blood-thinning medication — deserve clinical assessment. True fever, especially in a young child, is a medical question first and a heritage topic a distant second. And the standing rule above everything: this page is educational, self-acupressure is comfort-oriented daily care rather than diagnosis or therapy, and persistent symptoms belong with a licensed practitioner. A knuckle hollow makes a poor clinic; save the real clinics for the professionals who staff them.
Erjian — literally “two intervals” — waits in the shallow dip on the thumb side of the index finger, just beyond the big knuckle where pale palm skin meets the darker back of the hand. Classical practice kept this small spring point close for toothache, nosebleed, and feverish states. This guide walks through finding it by touch and pressing it safely at home.
Self-care limits
Frequently asked
- How do I find Erjian without measuring anything?
- Make a soft fist and use the big knuckle of the index finger as the entire map. Slide to its thumb-facing side, walk just past the rounded crest toward the fingertip, and settle into the shallow dip you find there, checking that it lies on the faint boundary between palm-coloured and hand-back skin. Nothing needs measuring: the cun language in formal locations encodes the same landmarks proportionally.
- Is pressing so close to a joint really safe?
- Gentle fingertip pressure held on intact skin is generally reasonable self-care for healthy adults, and this point’s superficial nerve supply means sensation arrives early, long before any force would matter. The realistic risks come from hard or repeated jabbing on a small joint, which the technique simply excludes. Respect the stop signals — sharp pain, lingering tingling, discomfort that worsens — and finish the session immediately if any appear.
- What did classical practice use Erjian for?
- The traditional record lists toothache, nosebleed, febrile disease, eye disorders, and periarthritis of the shoulder. Classical frameworks explain the grouping: the channel was drawn through the gums and ending beside the nose, and spring-point doctrine associated this class of points with hot states. Those are traditional ways of mapping the body, documented for context — not evidence-backed treatment claims.
- Why would a point on the index finger relate to teeth and the nose at all?
- In classical channel theory the large intestine meridian begins at the corner of the index fingernail and climbs the limb to the face, where texts describe it reaching the gums and finishing beside the nostril. Points near a channel’s start were read as relevant to regions along its whole route. It is a traditional geography of the body — helpful for understanding the literature, and distinct from anatomical cause and effect.
- Can acupressure at Erjian take the place of seeing a dentist?
- No. Self-acupressure offers comfort, not diagnosis, and a toothache with swelling, fever, or pain that disturbs sleep or lasts beyond a day or two needs professional assessment promptly. Picture two floors of one building: daily self-care lives downstairs, and clinical dentistry keeps the consulting room upstairs for when symptoms persist or escalate. Neither replaces the other, and the downstairs tenant should always send serious matters upstairs.
Sources
- 01WHO Standard Acupuncture Point Locations in the Western Pacific Region (2008), World Health Organization — location conventions.
- 02A Manual of Acupuncture, Peter Deadman, Mazin Al-Khafaji and Kevin Baker — point-name tradition, five-phase spring-point classification, and channel context.
- 03aijiu-mpvue (MIT License) licensed dataset, entry for LI2 Erjian — location, point class, actions, and 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/li2/leaf.json
- GET /zh-hant/points/li2/leaf.json
- GET /zh-cn/points/li2/leaf.json
- /llms.txt — the index of every leaf
- JSON-LD in the page: MedicalWebPage, MedicalEntity and FAQPage
{
"id": "LI2",
"name": {
"en": "Erjian",
"gloss": "Second Space",
"zh-Hant": "二間",
"zh-Hans": "二间"
},
"channel": {
"id": "LI",
"order": 2,
"of": 20
},
"location": {
"text": "Make a loose fist: on the thumb side of the index finger, just in front of the big knuckle, where palm skin meets back skin."
},
"for": [
"toothache",
"nosebleed",
"sore eyes"
],
"press": {
"text": "Fingertip pressure into the hollow, about a minute each hand.",
"seconds": 60,
"sides": "both"
},
"cautions": [],
"source": "Zhenjiu Jiayi Jing, book 3",
"url": "https://acupoints.com/en/points/li2",
"lastReviewed": "2026-08-24"
}