The Secret of the Wrist
Pulse diagnosis is one of the most refined diagnostic techniques in Traditional Chinese Medicine. By feeling specific points on both wrists with three fingers, a skilled therapist can distinguish between dozens of different energetic states. One of the most subtle distinctions is between Emptiness-Heat in the kidneys and Fullness-Heat in the liver.
Deficiency Heat in the Kidneys: Heat from Lack
Void heat is not caused by an excess of heat, but by a deficiency of cooling, nourishing substances. When the yin (the cooling, moisturizing energy) of the kidneys becomes depleted, the body loses its ability to regulate its normal body temperature. The result is a mild but persistent heat that occurs primarily in the evening and at night.
When feeling the pulse in kidney yin emptiness with emptiness heat, the therapist feels something remarkable: the pulse is rapid (over 80 beats per minute), yet simultaneously weak and thin. It feels shallow or even “floating”—as if it could easily slip away from under your fingers.
Crucially, the pulse becomes weak under pressure. When you press harder, the pulse almost disappears. This reveals that there’s no substantial force behind the speed—it’s an empty speed, driven by a lack of anchor rather than by force.
The pulse can also have a “fine” or “thready” quality, meaning it’s barely palpable, like a thin thread under the fingers. This reflects the depleted state of the substance in the body.
Volte-Heat in the Liver: Heat from Excess
Liver heat, on the other hand, is an excessive heat pattern. There is a real buildup of heat and tension that manifests as intense symptoms: red eyes, headaches, tinnitus, a bitter taste in the mouth, a fiery red complexion, intense irritability, and possibly even high blood pressure.
The pulse of liver fire feels dramatically different: it’s not only fast, but also powerful, full, and tense. The characteristic feature is the “wiry” (tense) quality—the pulse feels like a tightly wound string, stiff and resistant under your fingers.
When you apply pressure, this pulse remains strongly palpable. It doesn’t disappear but actively pushes back against your fingers. This reveals that there is substantial force and excess behind the symptoms.
The pulse can also be “rapid” and “surging” in the liver position (the left wrist, most distal). It feels full and prominent, sometimes almost throbbing.
The Crucial Differences
The fundamental distinction lies in three dimensions:
Power: Void heat feels weak and weakens with pressure. Full heat feels strong and remains strong with pressure.
Times: Void heat feels thin and superficial. Full heat feels full and firm.
Response to pressure: Void heat dissipates under pressure (void beneath the surface). Full heat persists or pushes back (actual substance).
Clinical Context
With void heat, the symptoms are also more subtle: a slight fever, especially in the afternoon and evening, night sweats, a dry throat at night, a feeling of heat in the palms of the hands and soles of the feet, restlessness without real irritation, and a red tongue without coating.
In full heat, symptoms are explosive: severe headache, red face, bloodshot eyes, loud voice, violent outbursts of anger, constipation, dark colored urine, and a red tongue with a thick yellow coating.
Therapeutic Consequences
This wrist distinction is essential for the correct approach. Emptiness heat requires nourishment of the yin and gentle cooling—formulas such as Zhi Bai Di Huang Wan. Aggressive cooling is said to aggravate the underlying emptiness.
Volte heat, on the other hand, requires powerful heat clearing formulas like Long Dan Xie Gan Tang. Nourishing treatments would only trap and aggravate the heat.
So the pulse not only tells us what is going on, but especially how powerful the intervention should be and in which direction: tonifying or reducing, feeding or clearing.