A quiet but useful chest point on the Spleen Meridian (SP), Tianxi (SP-18) sits along the side of the chest and is called upon whenever the breast or chest needs local attention — especially for nursing mothers with blocked milk flow or breast pain.
Name & story
The name 天溪 Tianxi means "Heavenly Stream" — 天 tiān means heaven or sky, and 溪 xī means a stream or brook. Imagine a gentle mountain stream flowing down from a high, clear place. The point sits on the chest, the upper part of the body, which in Chinese cosmology corresponds to Heaven. And the character for stream evokes the flowing of Qi and milk through the breast — a natural, easy current that this point helps to restore when things become blocked or sluggish.
Point family & character
Tianxi (SP-18) belongs to the Spleen Meridian (SP). It is a local chest point on the channel, situated on the lateral chest wall as the Spleen channel travels upward toward the armpit.
Five-element dynamics
The Spleen belongs to the Earth element and is the great transformer of nourishment in the body — it turns food and drink into Qi and Blood (Xue) and distributes them everywhere. Breast milk is considered an expression of Blood (Xue) in Chinese medicine, transformed by the Spleen and Stomach and flowing under the influence of the Liver. When that flow is smooth, milk comes freely; when Qi Stagnation or obstruction blocks the channel in the chest, pain and insufficient lactation follow. Tianxi (SP-18), sitting directly over the breast, addresses that local flow.
Location
Tianxi (SP-18) is found on the chest, in the fourth intercostal space — the gap between the fourth and fifth ribs — along a vertical line 6 Cun from the midline (the midclavicular line or just lateral to it). It lies at the same level as the nipple in most people.
Anatomy & fascia
The point lies on the lateral chest wall, in the intercostal space between ribs, in the region of the pectoralis major muscle.
Needling
The needle is inserted obliquely or transversely along the intercostal space, with care taken not to angle it toward the chest cavity.
Safe depth
0.3–0.5 Cun, directed obliquely along the intercostal space.
The golden tip
Nursing mothers experiencing breast tenderness or sluggish milk flow can gently press or massage the area of SP-18 — in the fourth intercostal space, roughly level with the nipple, toward the side of the chest. A few minutes of gentle circular massage can help ease local tension and encourage flow. Always consult a practitioner if pain is severe or accompanied by fever.
For education only — not medical advice. Consult a qualified practitioner.