Not over broken or inflamed skin.
血海 Xuehai
“Sea of Blood” · SP10
Foot Taiyin · 10 of 21
Where. Knee bent: three finger-widths above the inner top corner of the kneecap, on the bulge of the thigh muscle.
For. Period pain, irregular periods, itchy skin rashes.
Press. Two finger pads, slow circles, one minute each leg.
Caution. Not over broken or inflamed skin.
血海，在膝臏上內廉白肉際二寸中按 · Press with me
Six slow breaths
About a minute. Press as you breathe out, ease as you breathe in.
鄰 · Neighbouring leaves
Where Xuehai Sits Above the Inner Knee
The dataset locates SP10 with the knee flexed, on the medial aspect of the thigh — the inner side — two cun above the medial end of the patellar base, resting on the bulge of the medial head of quadriceps femoris. Unpacked landmark by landmark: the patellar base is the upper rim of the kneecap, and its medial end is the top-inner corner of that rim. From that corner, two cun measures straight up the thigh toward the hip. A cun is the proportional body-measure of Chinese point-location, taken from the person being examined rather than from a ruler; the thumb-width convention makes one cun roughly the width of your own thumb across the knuckle, so two cun is a comfortable two-thumb span for most hands. Because the measure is proportional, the absolute distance varies from body to body — the point lives in your coordinates, not in centimeters.
What lies under the fingertips is unusually friendly terrain. The spot sits squarely on the fullness of the quadriceps — specifically the medial head of quadriceps femoris, the teardrop-shaped muscle that rounds out above and beside the inner knee. There is thick muscle here, then bone, and the great cavities of the chest and abdomen lie far away; unlike the rib-fringed points of the chest wall, nothing delicate waits just beneath a thin membrane. Fittingly for a page built on gentle self-care, the licensed dataset records no specific caution for this point. That absence is worth stating plainly, and equally worth not overstating: it licenses light surface contact, never force, and every other boundary on this page still applies.
Channel context explains why a thigh point carries such a watery title. Classical teaching draws the spleen channel ascending from the big toe, climbing the inner leg through ankle, calf, and knee, crossing the medial thigh, and continuing up toward the chest — the registry’s own course summary reads the channel as rising from the big toe up the inner leg to the chest. Xuehai stands on the knee-to-thigh stretch of that climb, where the channel leaves the joint behind and moves through broad muscle. In the traditional frame this stretch of route belongs to the part of the journey associated with the spleen system’s stewardship of digestion, blood, and women’s health — themes that dominate the point’s recorded portfolio.
A Self-Palpation Walkthrough
Sit on a firm chair and let the knee bend comfortably, foot flat on the floor or heel drawn slightly back, so the thigh softens. Place your opposite hand on the inner side of the knee and find the kneecap first — slide up its border until you reach the top rim, the patellar base, then walk to the innermost corner of that rim. From that corner, measure straight up the thigh toward the hip: two thumb-widths, stacked heel to tip, pressed lightly end to end. Where the second thumb-width ends, settle your fingertips into the flesh and feel for the rounded fullness beneath — the bulge of the medial head of quadriceps femoris. That muscle-belly spot, two cun above the kneecap corner on the inner thigh, is the location the dataset describes.
Two confirmations help before any pressing begins. First, the muscle test: keeping your fingertips in place, slowly straighten the knee and let it bend again. The fullness under your fingers firms and relaxes with the movement — that is the quadriceps reporting for duty, and it confirms you are on muscle rather than tendon or bone. Second, compare sides. Locate the mirror-image spot on the other thigh and touch both feather-light; most people notice a faint, dull awareness at the true point and little sensation a thumb-width away. The spot should sit unmistakably above the kneecap rim, clear of the joint line — if your finger is level with the kneecap itself, you have measured short.
The classic errors are few and easy to correct. One is measuring sideways around the leg instead of vertically along the thigh’s long axis; the direction is strictly up toward the hip from the kneecap corner. Another is landing too low, right on the rim of the kneecap or on the gristle at its edge, where the tissue is thin and unyielding — slide up another thumb-width into the muscle. A third is drifting too far toward the front or back of the thigh; the point keeps to the inner face. When in doubt, return to the top-inner corner of the kneecap, breathe out, and measure up once more, slowly.
Reading the Name: Sea of Blood
The two characters carry the whole image. Xue 血 means blood — one of the oldest characters in the language, its older graphic forms picturing a vessel of blood set out in ritual. Hai 海 means sea or ocean, the vast water that gathers every river’s flow. Together, Xuehai reads as the Sea of Blood: the place where, in the classical picture, the blood-like aspect of the channel’s wealth gathers as rivers gather into an ocean. Point names in this tradition are rarely arbitrary labels; they are compressed teachings, and this one announces its theme before any indication list is consulted — wherever the body keeps a sea, the tradition expects tides, currents, and the consequences of a sea that runs dry or floods.
Classical texts describe certain sites as gathering places where the deeper aspects of a channel pool close to the surface, and this point held that office in discussions of the blood. The surrounding theory completes the frame: traditional teaching assigns the spleen system the role of governing blood — keeping it circulating within its pathways rather than straying — and links the spleen channel closely to digestion, nourishment, and women’s health. Read through that lens, a point named Sea of Blood standing on the spleen channel becomes almost self-annotating: when classical practice discussed irregular cycles or blood-depleted complexions, this was a station the conversation returned to. These are traditional frameworks for understanding the body, offered for orientation — not physiology claims.
Pinyin renders the name Xuèhǎi: xuè carries the falling fourth tone, hǎi the dipping third tone that dips low before rising again. The hanzi pair 血海 is compact enough to memorise at a glance. Like the gates, valleys, wells, and marshes scattered through the point canon — and the neighboring waters of the lower limb, springs and yin-seas among them — the sea metaphor does real work here. It tells you how the tradition ranked this spot: not a way-station things pass through, but a reservoir things collect in. Names that promise gathering are names that invite unhurried attention.
Traditional Indications, Explained
The recorded indications number nine: irregular menstruation, dysmenorrhea, amenorrhea, urticaria, eczema, erysipelas, orchitis, anemia, and ulcers of the lower leg. Grouped, they tell a coherent story. Three concern the menstrual cycle itself — periods arriving unpredictably, painfully, or not at all. Three concern the skin breaking out — hives that rise and fade, eczema that itches and weeps, and erysipelas, the hot, bright-red inflammation the old books described vividly. The remainder reach further: orchitis, anemia, and chronic ulcers of the lower leg. One point gathering such a spread looks scattered until the name is remembered — every item sits somewhere in the traditional territory of blood and its movements.
The traditional reasoning ran something like this, reconstructed from the general logic of the literature rather than any single citation. For the menstrual cluster: the spleen was said to govern blood and the channel’s course ties the leg to the body’s central systems, so cycle disturbances were approached along the spleen pathway, and the Sea of Blood stood at the head of those discussions. For the skin cluster: eruptive, migrating, heat-flavored rashes were read as commotion within the blood aspect itself, and calming or regulating the sea was the classical response — the tide settles when the sea is treated, not the foam. Anemia and slow-healing leg ulcers were folded into the same picture as signs that the blood failed to nourish skin and flesh. Each step is a traditional inference, documented for understanding.
Honesty requires drawing a bright line around three items in particular. Erysipelas and orchitis are, in modern understanding, infections and inflammations that call for prompt medical assessment and treatment; anemia has causes that range from diet to conditions needing investigation; and a lower-leg ulcer that resists healing needs wound care, not pressure nearby. The record preserves these entries because they map how classical practice thought, not because self-applied pressure addresses them. Where modern research touches self-applied acupressure at all, reviews suggest effects are modest and context-dependent, and evidence specific to any single point remains thin. Hold the tradition as history and craft; hold the medical boundary as firm.
Self-Care Acupressure at Home
With the point located by the walkthrough above, settle in: seated, spine tall but unforced, thigh supported and released. Curl your index and middle fingers together and rest the pads — not the tips — on the muscle fullness. Begin with contact alone for a few slow breaths, then add small circles, letting the skin glide over the muscle beneath. Pressure should register as pleasant dullness or mild warmth, never sharpness. A common home rhythm is one to three minutes per side, once or twice daily, timed where possible to slow exhales so each circle rides the breath out. Swap hands, find the mirror spot, and give the other thigh the same unhurried attention.
Quality outranks duration. Light, patient, regularly repeated contact fits the wellness register this page practises; hard jabbing teaches the body nothing and risks bruising the very muscle you mean to soothe. Warm your hands first on cold days, because chilled muscle guards itself. Choose a quiet corner over a screen, and consider anchoring the practice to something you already do daily — after washing up in the morning, or during the evening wind-down — because in self-care traditions consistency, not intensity, is the virtue that compounds. Two minutes daily beats twenty minutes once a fortnight, and the ritual itself is half the benefit claimed for it.
Treat the practice as a few minutes of attending to yourself rather than a treatment session. Across a few weeks you may notice the area feeling less guarded, the legs feeling lighter in the evenings, or nothing at all except that you showed up for yourself each day. Every one of those outcomes sits inside the honest scope of self-acupressure. What sits outside it is escalation — pressing harder, longer, or deeper to force a result, especially around the days of a difficult cycle. When curiosity pulls that way, return to gentleness, shorten the session, or rest the practice entirely for a day or two.
Cautions and Safe Practice
Begin with what the record says, because it is genuinely useful: the licensed dataset records no specific caution for SP10. Nothing in this entry’s source material warns of danger at this site, and the geography supports the calm reading — the point lies over thick thigh muscle, well away from the chest wall, the abdominal organs, and every structure that makes some other points unforgiving. But absence of a recorded caution is not an invitation to force. Every rule that governs gentle self-care everywhere applies here in full: this is surface work, done with finger pads, on healthy skin, by someone simply tending their own body.
The universal boundaries, spelled out. Stop at once on sharp, electric, or radiating sensation, and do not resume that day. Skip the point over broken, irritated, or infected skin — and given the point’s skin-themed traditional portfolio, respect that rule doubly. Pause the practice during feverish illness, and be cautious for a stretch after any thigh injury or surgery until ordinary movement is comfortable. Pregnant readers should consult a qualified practitioner before adding any new point practice, as a matter of general prudence rather than a recorded warning about this point. Anyone living with a diagnosed bleeding disorder, or taking prescribed medication with blood-thinning effects, does better to ask their clinician before regular deep-tissue pressure of any kind — a general caution about pressure practices, not a special property of this point.
And the wider rule stands over everything: this page is educational, and acupressure is self-care, never diagnosis or therapy. Seek prompt medical care — not a pressure routine — for period pain that stops you living normally or worsens month over month; cycles that cease unexpectedly without an explanation you already know; heavy bleeding that soaks through protection hour after hour; skin outbreaks that spread quickly, blister, or come with fever; testicular pain or swelling; a leg ulcer that will not close; or tiredness with pale complexion and breathlessness on small efforts. Persistent symptoms belong with a licensed practitioner. The Sea of Blood offers most people a quieter gift than miracles: a few honest minutes of care for the legs that carry them, practiced safely.
Xuehai — the Sea of Blood — rests on the soft inner sweep of the thigh just above the knee, along the spleen channel’s ascent from the big toe toward the chest. Classical practice reached for it when cycles faltered, periods pained, or skin flared in restless patches. This guide walks you through finding it by touch and pressing it gently.
Self-care limits
Frequently asked
- How do I find Xuehai without knowing anything about cun?
- Use the kneecap as the whole map. Slide your fingers up the inner border of the kneecap to its top rim, find the top-inner corner, then stack two thumb-widths straight up the thigh toward the hip. Settle your fingertips into the rounded muscle fullness there, and confirm it by straightening and bending the knee slightly — the spot firms under your fingers. That corner-plus-two-thumb-spans recipe reproduces the recorded two-cun measurement without any ruler.
- Is pressing Xuehai myself actually safe?
- Gentle fingertip pressure held on the surface is reasonable self-care for healthy adults, and notably, the licensed dataset records no specific caution for this point — it sits on thick muscle, far from the vulnerable structures that make chest and neck points demanding. Reasonable is not unconditional, though: keep pressure light, stop on sharp sensation, avoid broken or infected skin, and pause during fever or after a fresh thigh injury.
- What did classical practice use Xuehai for?
- The traditional record lists irregular menstruation, dysmenorrhea, amenorrhea, urticaria, eczema, erysipelas, orchitis, anemia, and ulcers of the lower leg. Classical teaching grouped them under the banner of blood and its orderly movement — the spleen governing blood, the sea gathering it — which is why menstrual and skin complaints fill most of the historic portfolio. Those are traditional frameworks, preserved for context and cultural understanding, not evidence-backed treatment claims.
- Why would a thigh point be called the Sea of Blood?
- Because the name encodes the theory. Classical texts describe certain sites where a channel’s deeper riches gather close to the surface, the way rivers gather into a sea, and this point held that role in traditional discussions of blood. Standing on the spleen channel — the system traditionally charged with governing blood — the name reads less like poetry and more like a filing label. The tradition named its map honestly: seas collect, and this was where blood was thought to collect.
- Can acupressure at Xuehai replace seeing a doctor about my cycle?
- No. Self-acupressure is a comfort practice, not a diagnostic tool, and cycle problems deserve real answers: sudden cessation of periods, severe or worsening pain, unusually heavy bleeding, or bleeding between periods all merit professional assessment promptly. Think of the two as different rooms in the same house of care — daily self-soothing lives in the kitchen, clinical medicine keeps the consulting room — and neither substitutes for the other.
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, blood-sea imagery, and channel context.
- 03aijiu-mpvue (MIT License) licensed dataset, entry for SP10 Xuehai — location, actions, and indication 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/sp10/leaf.json
- GET /zh-hant/points/sp10/leaf.json
- GET /zh-cn/points/sp10/leaf.json
- /llms.txt — the index of every leaf
- JSON-LD in the page: MedicalWebPage, MedicalEntity and FAQPage
{
"id": "SP10",
"name": {
"en": "Xuehai",
"gloss": "Sea of Blood",
"zh-Hant": "血海",
"zh-Hans": "血海"
},
"channel": {
"id": "SP",
"order": 10,
"of": 21
},
"location": {
"text": "Knee bent: three finger-widths above the inner top corner of the kneecap, on the bulge of the thigh muscle."
},
"for": [
"period pain",
"irregular periods",
"itchy skin rashes"
],
"press": {
"text": "Two finger pads, slow circles, one minute each leg.",
"seconds": 60,
"sides": "both"
},
"cautions": [
"Not over broken or inflamed skin."
],
"source": "Zhenjiu Jiayi Jing, book 3",
"url": "https://acupoints.com/en/points/sp10",
"lastReviewed": "2026-08-24"
}