Lidui

What is ST45?

ST45 (Lidui) is the final point of the Stomach channel, sitting at the outer corner of the second toenail.

Its Chinese name, Lidui, is often rendered as "Severe Mouth" or "Strict Exchange". In classical theory it is a jing-well point, the place where the channel's energy is said to begin or end. Points of this type were traditionally used for sudden, acute and "upper body" complaints even though they sit at the far end of a limb.

Classical texts link ST45 to toothache and gum pain, facial swelling, nosebleed, fever, abdominal fullness, and disturbed sleep with vivid dreams or nightmares. It appears in most standard point lists and is taught on every acupuncture curriculum, so its traditional standing is high.

That standing needs to be read carefully. A point being old, famous and universally taught tells you that generations of practitioners used it. It does not show that pressing it changes anything in the body, and it is not a safety record either. Safety depends on your own feet, your circulation and your skin, not on the point's pedigree.

The honest verdict on evidence is short. We found no controlled human trial testing finger pressure at ST45 for any condition. It sometimes appears inside multi-point protocols in research, which cannot tell you what this one point contributed. Acupressure evidence in general is dominated by small, unblinded, short-term studies, and ST45 has less than most.

So treat this page as a map rather than a prescription. ST45 is easy to find, costs nothing, and self-applied finger pressure on healthy skin is low risk for most people. Anything beyond that — a claim that it stops toothache or ends nightmares — is tradition speaking, not trial data. Use it alongside proper care for the problem you actually have, never instead of it.

Where is ST45 and how do you find it?

ST45 sits on the second toe, at the outer corner of the toenail — the side facing the little toe — about 2 mm from the nail's edge.

• Count to the right toe. Start at the big toe and move outward one toe. The second toe is the one next to the big toe, and ST45 belongs to that toe only.
• Find the nail corner. Look at the far corner of the second toenail on the outside of the foot, away from the big toe. That corner is your landmark.
• Step back a fraction. Classical texts place the point 0.1 cun from the nail corner. In real terms that is roughly 2 mm, or about a tenth of a thumb-width, diagonally down and back from the corner onto the skin.
• Land on skin, not nail. The point is on the soft skin beside the nail bed, not on the hard nail plate itself. Your fingertip should feel give, not a flat shell.
• Check for tenderness. Many people notice this spot is a little sharper than the skin around it. Tenderness is a helpful hint, but it is not proof you are on the point.

Comparison helps if you are unsure. The matching corner of the big toe is a different point entirely, and the inner corner of the second toe is not ST45. Only the outer, little-toe-side corner of the second toe is agreed on across sources.

Sit down to find it. Cross one ankle over the opposite knee so the toe comes to you, rather than bending double over your foot. Good light and clean, dry skin make the nail corner much easier to see, especially if you have thick or discoloured nails.

This page describes self-applied finger pressure only. Nothing here involves needles, skin-breaking or heat of any kind.

How do you apply pressure to ST45?

1. Get set up. Sit with your foot resting on the opposite thigh or on a low stool. Wash and dry your hands and the toe first, and make sure your fingernails are short enough not to dig in.
2. Place your thumbnail edge. Rest the flat pad or the side of your thumb on the skin just beside the outer corner of the second toenail. A fingertip works just as well if your thumb feels clumsy on a small toe.
3. Use a pinch grip. Support the underside of the toe with your index finger while your thumb presses from above. Pinching gives you control and stops the toe bending sideways at the joint.
4. Press firmly, not sharply. Aim for a dull, definite ache you could hold a conversation through. On a scale of ten, around three or four. The toe should never feel like it is being stabbed.
5. Hold and release. Hold steady for 20 to 30 seconds, release for 10, and repeat two or three times. Small circles with the thumb pad are an alternative if steady pressure feels too intense.
6. Do both feet. Most traditional use treats the point on both sides. Repeat the whole sequence on the other second toe.
7. Keep sessions short. Two or three minutes per foot, once or twice a day, is plenty. More pressure and more repetitions do not make it work better and do make soreness more likely.

Stop straight away if you feel sharp or shooting pain, if the skin reddens and stays red, if the toe starts to throb, or if you feel faint or lightheaded. Stop too if you cannot clearly feel your toes, because you cannot judge safe pressure without sensation.

Check the toe afterwards. Any bruise, broken skin or lingering tenderness the next day means you pressed too hard, so ease off or leave the point alone for a few days. Finger pressure is the only technique described here.

What is ST45 traditionally used for?

• Toothache and gum pain. The Stomach channel is described as running through the gums and jaw, so ST45 was used for upper tooth and gum pain. There is no trial testing acupressure at ST45 for dental pain, and nothing here treats the infection or decay causing it.
• Nightmares and restless sleep. Classical texts list ST45 for dream-disturbed sleep, waking in fright and an agitated mind. This is one of its best-known traditional uses, but we found no human study measuring sleep quality after pressing this point.
• Facial swelling and jaw tension. Tradition sends distal points like ST45 to problems at the far end of the same channel, including a swollen face or tight jaw. Evidence for this specific effect is absent.
• Fever and acute illness. Jing-well points were classically used in sudden febrile illness. Older records describe needling or bleeding techniques, not finger pressure, and no controlled research supports self-applied pressure here for fever.
• Nosebleed. Some classical lists include epistaxis (nosebleed) among ST45's uses. A nosebleed is managed by pinching the soft part of the nose and leaning forward, and pressing a toe is not a substitute for that.
• Abdominal fullness and poor appetite. As a Stomach channel point, ST45 appears in formulas for bloating, belching and loss of appetite. Digestive acupressure research almost always uses other points, so this claim rests on tradition alone.
• Mental agitation. Texts mention mania, anxiety and an overheated, over-thinking mind. Any calming people notice from a few minutes of quiet self-massage is plausible but not specific to ST45.

Read the pattern honestly. ST45 has a wide and respected traditional reputation and almost no direct human evidence behind any single use. That does not make pressing it pointless, but it does mean you should not expect a measurable result, and should not delay dental, medical or mental health care while you try.

Are there tips for using ST45 effectively?

• Trim the nail first. A long or jagged second toenail makes it hard to reach the skin at the corner and easy to scratch yourself. Cut nails straight across, which also reduces ingrown-nail risk.
• Warm your feet. Cold toes are numb toes, and numb toes are harder to judge pressure on. A warm foot bath or a few minutes in socks before you start makes the point easier to feel.
• Use a pinch, not a jab. Supporting the toe from underneath while you press from above spreads the load. It protects the small joints and gives steadier pressure than poking downward.
• Keep sessions short and regular. Two or three minutes a day for a fortnight tells you more than one long, painful session. Short and frequent is the usual pattern in acupressure instruction.
• Pair it with the real fix. If you are using ST45 for toothache, book the dentist. If you are using it for nightmares, look at sleep timing, alcohol and screen use too. Acupressure works best as an add-on, never a replacement.
• Write down what happens. Note the date, how long you pressed and how you felt an hour later. A simple log stops you fooling yourself in either direction about whether it helped.
• Check the skin each time. Give the toe a quick look before and after. Redness that fades in minutes is fine; anything that lasts, breaks or weeps means stop.
• Try the other side. Some people find one foot more tender than the other. Treat both, and do not force extra pressure on the duller side to make them match.
• Respect your own feedback. If pressing ST45 consistently makes you feel worse, queasy or lightheaded, that is a reason to stop using it, not a sign it is working.

What do people get wrong with ST45?

• Pressing the wrong toe. ST45 is on the second toe only. Videos often blur past this and people end up on the big toe or the third toe, which are different points entirely.
• Choosing the inner corner. The agreed location is the outer corner of the second toenail, the side facing the little toe. The inner corner, nearer the big toe, is not ST45.
• Pressing on the nail plate. Jamming a thumb onto the hard nail does nothing except hurt the nail bed. The point lies on the soft skin just beyond the nail corner.
• Expecting a cure. ST45 will not cure toothache, stop an infection or guarantee a dream-free night. Anyone promising that is overselling a point with almost no trial evidence behind it.
• Using far too much force. A toe is small and the bones are close to the surface. Digging in with a fingernail risks bruising, broken skin and an infection that is far worse than the original complaint.
• Ignoring numb feet. People with reduced sensation, often from diabetes, cannot feel when pressure becomes damaging. Skipping that check is the most common genuinely risky mistake on this point.
• Delaying real care. Pressing a toe for three days while a dental abscess grows is dangerous. Acupressure is an add-on, and tooth, jaw and facial swelling need proper assessment.
• Treating damaged skin. People press straight over an ingrown nail, a fungal nail or a blister because that is where the point is. Work around broken or infected skin or leave the point alone.
• Using heat or sharp tools. Some sources describe bleeding or burning techniques at jing-well points. None of that belongs in self-care, and nothing on this page involves breaking the skin.

What does the research on ST45 actually say?

The straight answer is that we found no controlled human trial testing finger pressure at ST45, on its own, for any condition. That is not a gap in this page; it is a gap in the literature.

ST45 does appear in research as one point among many. Acupuncture studies of digestive complaints, facial pain and acute illness sometimes include whole Stomach channel protocols that contain ST45 alongside several other points. When a trial needles six or eight points together, it cannot tell you what any single point contributed, so those results say nothing specific about ST45.

A second strand involves the jing-well points as a group. In classical and some modern Chinese practice the twelve jing-well points, including ST45, are stimulated together in sudden collapse or stroke-type presentations, often with skin-breaking techniques performed by practitioners. Reports of this work are mostly small, poorly controlled, and describe procedures that have no self-care equivalent. They are not a reason to press your toe in an emergency.

It is worth knowing what good acupressure evidence looks like, for comparison. PC6 and nausea is the clearest example in the whole field: multiple randomised trials and systematic reviews show a real, if modest, effect on nausea and vomiting, particularly after surgery and in pregnancy. ST45 has nothing remotely like that behind it.

The wider acupressure literature is also weaker than it first looks. Most trials are small, cannot blind participants to whether they were pressed, rely on how people rate their own symptoms, and follow up for days rather than months. Expectation and attention alone produce real changes in those measures.

What this means for you is simple. If you want to try ST45, treat it as a low-cost experiment with an unknown result rather than a treatment with a track record. Judge it on your own log over a couple of weeks, and keep the medical or dental care your symptom actually needs running alongside it.