Yixi

What is BL45?

BL45 (Yixi) is a point on the Bladder channel of the upper back, four finger-widths out from the spine at about the level of the sixth thoracic vertebra.

It sits on the outer of the two Bladder channel lines that run down each side of the spine. The inner line carries the well-known "shu" points; the outer line, where BL45 lies, is traditionally described as governing the spirit and breath aspects of the organ at the same level. BL45 is paired with the heart and chest region.

The name Yixi is usually translated as "Yi Xi" — the sound of a sigh or a wince. The classical story is that pressing the spot makes the patient make that noise. Traditional texts list it for cough, wheezing, chest and upper-back pain, night sweats and fever.

Here is the honest verdict on the evidence: there is essentially no human research on BL45 specifically. Its traditional standing tells you that practitioners have used it for a long time. It does not tell you that it works, and it does not tell you that it is safe for you. Those are two separate questions, and tradition answers neither. Points on the upper back sit over ribs, muscle and, in some people, fragile bone, so the safety question is real.

What you can reasonably expect from firm finger pressure here is what you would expect from firm pressure on any tight patch of upper-back muscle: some short-term easing of local tightness, for some people, for a while. That is a modest claim, and it is the one the evidence supports. If you came to this page after seeing BL45 described as a treatment for asthma or a fix for a long-standing back problem, treat that claim as unproven.

Everything described on this page is self-applied finger pressure, or pressure from a partner or a ball against a wall. Nothing here involves needles.

Where is BL45 and how do you find it?

BL45 sits about four finger-widths to the side of the spine, level with the sixth thoracic vertebra, near the inner edge of the shoulder blade.

• Find the bottom tip of your shoulder blade. Reach across your back, or have someone look. With your arm relaxed at your side, the lowest point of the shoulder blade sits roughly level with the seventh thoracic vertebra.
• Count up one vertebra. From that level, move one bump up the spine. That bump is the spinous process of T6, the bony knob you can feel under the skin. BL45 is level with its lower edge.
• Measure out from the midline. Traditional texts place BL45 three cun lateral to the spine. In practical terms that is four of your own finger-widths held together, or roughly 6 to 7 centimetres on an average adult.
• Check against the shoulder blade edge. That distance usually lands you at or just inside the inner (medial) border of the shoulder blade. On many people BL45 is in the soft tissue right at that edge.
• Feel for the response. The spot is often a tender, slightly ropey band of muscle. It frequently feels sore in people who work at a desk, which is a sign of muscle tension rather than proof you have found the point.

BL45 is on the outer Bladder line. The inner line point at the same level, BL15, sits two finger-widths from the spine — closer in. If you are not sure which you are on, stay with the wider measurement and work the soft tissue near the scapular edge rather than hunting for a precise spot.

Both sides of the body have a BL45. It is an awkward place to reach on yourself, which is why most people use a tennis ball against a wall instead of fingers.

How do you apply pressure to BL45?

1. Get someone to help, or use a ball. BL45 sits where your own fingers barely reach. A partner's thumb works well. On your own, place a tennis ball or massage ball between your upper back and a wall, then lean gently.
2. Warm the area first. Roll your shoulders back a few times and take two slow breaths. Pressing into a cold, braced upper back is less comfortable and less useful.
3. Settle into the soft tissue. Aim for the muscle beside the spine, not the knobs of the spine itself. You should feel give under the pressure, not hard bone.
4. Press firmly but not sharply. A useful level is a 4 to 6 out of 10: clearly felt, slightly sore, and something you could hold a conversation through. Sharp or breath-catching pain means back off.
5. Hold, then release. Keep steady pressure for 20 to 60 seconds, or make small slow circles. Breathe out as you press in. Release slowly rather than jerking away.
6. Repeat on the other side. Most people do both sides for balance, two or three rounds each.
7. Keep sessions short. Two to five minutes in total, once or twice a day, is plenty. More is not better here, and upper-back tissue bruises easily.

Stop straight away if you feel pins and needles, shooting pain down an arm, dizziness, or any change in your breathing. Stop also if the skin stays red and sore an hour later, and leave at least a day before trying again.

Fingers, thumbs, knuckles or a ball only. Never use anything that breaks the skin, and do not press into this area with a hard edge or tool point.

What is BL45 traditionally used for?

• Cough and wheezing. Classical texts list BL45 for cough, shortness of breath and chest fullness, because of its position over the upper chest region. No human trial has tested finger pressure at BL45 for any breathing problem. Asthma and persistent cough need medical assessment, not pressure points.
• Upper back and shoulder blade pain. This is the use with the most everyday plausibility. BL45 sits in the muscle that most often goes tight between the shoulder blades. Firm pressure on tight upper-back muscle does ease stiffness for some people in the short term, though the research on massage and trigger-point pressure is mostly small and unblinded, and the benefit tends to fade within hours to days.
• Chest and rib-cage tightness. Tradition links BL45 to a sensation of constriction across the chest. There is no human evidence for this use. Any new or unexplained chest tightness is a reason to call a doctor, not to press a point.
• Night sweats and fever. Older texts list BL45 among points for heat conditions and sweating at night. There is no modern human evidence supporting it. Persistent night sweats have medical causes worth investigating.
• Emotional strain and sighing. The outer Bladder line points are traditionally connected to the emotional aspect of each organ, and BL45 is paired with the heart. Research on acupressure and anxiety exists in general, but it is small, short-term and has not isolated BL45. Any calming effect you feel is just as likely to come from the slow breathing and quiet time involved.

In short: BL45 has a long traditional résumé and a near-empty research file. The one thing it plausibly does is the thing any firm upper-back pressure does.

Are there tips for using BL45 effectively?

• Use a wall and a ball. This is the single most practical tip for BL45. A tennis ball between your upper back and a wall lets you control the pressure precisely by how much you lean, and it reaches a spot your fingers cannot.
• Work the whole band, not one dot. Precision matters less than people think. Slowly rolling the area between the inner edge of the shoulder blade and the spine covers BL45 and its neighbours, and usually feels better than hunting for one exact spot.
• Breathe out into the pressure. Press as you exhale and let the shoulder soften. Holding your breath tenses the very muscle you are trying to release.
• Drop the shoulder blade first. If you hunch, the shoulder blade covers the area and you end up pressing bone. Let the arm hang heavy, or reach the opposite arm across your chest to slide the blade outwards.
• Keep a simple record. Note your stiffness out of ten before and after for a week. If nothing shifts, BL45 is not doing anything for you, and the honest move is to try something else.
• Pair it with movement. Pressure plus some gentle shoulder blade squeezes or a doorway chest stretch tends to help more than pressure alone, and the movement has better evidence behind it.
• Mind the ribs. Below and lateral to BL45 the ribs sit close to the surface. If pressure starts to feel like it is on a bony bar rather than muscle, move back towards the spine a little.
• Stop when you are sore, not when the timer ends. Lingering soreness the next day means you went too hard. Less pressure, held a little longer, is the better pattern.

What do people get wrong with BL45?

• Expecting a cure. The commonest error. BL45 will not clear asthma, resolve a chest condition or fix a back problem that has lasted years. At best it offers short-term easing of local muscle tightness.
• Pressing on the spine itself. People aim for the bony knobs down the middle. BL45 is four finger-widths out to the side, in muscle. Pressure directly on the spinous processes is uncomfortable and pointless.
• Confusing it with BL15. BL15 sits on the inner line, two finger-widths from the spine at the same level. BL45 is the outer one. They are different points, and videos often mislabel them.
• Counting vertebrae from the wrong start. Starting from the big bump at the base of the neck and counting down is error-prone. The bottom tip of the shoulder blade is a more reliable landmark for finding the T6 level.
• Using a hard tool point. A cane knob or a pointed massager concentrates force onto ribs and bruises the area. Thumb, knuckle or a soft-ish ball is enough.
• Going too hard because it is sore. Tenderness here usually means tight muscle, not a point that needs crushing. Heavy pressure leaves bruising and makes the area guard up.
• Treating new chest symptoms at home. Pressing BL45 instead of getting unexplained chest tightness, breathlessness or a new persistent cough checked is the most dangerous mistake on this list.
• Overdoing the frequency. Several long sessions a day does not speed anything up. The upper back responds better to short, regular, moderate pressure.

What does the research on BL45 actually say?

There is no useful human research on BL45 specifically. No controlled trial, and no sizeable observational study, has tested finger pressure at BL45 for cough, asthma, chest tightness, sweating or back pain. That is the honest position, and it should shape what you expect.

What exists around the edges is broader and weaker. Manual therapy and trigger-point pressure on the muscles between the shoulder blades has been studied for upper-back and neck pain, and those studies generally show modest short-term relief. They are small, hard to blind, and they do not use acupuncture point maps, so they say something about pressure on that region rather than anything about BL45 as a point.

Acupuncture research involving the Bladder channel of the back exists too, mostly for back pain and some respiratory conditions. Those trials used needles, which is a different intervention from what this page describes, and BL45 is rarely among the points chosen. Where it does appear, it is one of several points in a combined prescription, so no conclusion can be drawn about BL45 on its own.

What "no evidence" means in practice: it does not prove the point is useless, and it does not entitle anyone to claim it works. It means the question has not been asked properly. For a reader, the sensible reading is that pressing BL45 is a low-cost, low-risk thing to try for upper-back tightness, with the expectation of a small and temporary effect, and no expectation at all for anything involving the lungs, heart or a long-term condition.

Be sceptical of any article or video that cites a specific study for BL45. Check whether it names the point, whether the study used pressure or needles, and whether it was controlled. Most such claims do not survive that check.