Diagnostics 诊法

The four examinations sì zhěn · 四诊

• Wang 望 — looking: complexion, body shape, movement, and above all the tongue.
• Wen 闻 — listening and smelling: voice quality, breathing, cough and odour.
• Wen 问 — asking: a long structured history — sleep, appetite, digestion, temperature preference, pain, emotions, menstrual history.
• Qie 切 — palpating: the pulse at three positions on each wrist, plus the abdomen and channels.

A practitioner is trained to combine all four into one pattern. Any single sign taken alone misleads.

Tongue diagnosis shé zhěn · 舌诊

The practitioner notes the tongue body (colour, shape, moisture, movement) and the coating (colour, thickness, distribution). In the model, body colour is read as reflecting deeper, longer-standing states and the coating as reflecting more recent digestive and fluid conditions.

Lighting, medication, coffee, smoking and even toothpaste change what is seen — which is why practitioners view the tongue as one input among four, never a verdict.

Pulse diagnosis mài zhěn · 脉诊

Three positions on each wrist are felt at three depths, giving twenty-eight classical pulse qualities — floating, deep, slippery, wiry and so on.

It is the most skill-dependent part of the tradition, and studies of agreement between practitioners have generally found lower consistency than the classical literature implies. Modern medicine reads the pulse for rate and rhythm; the TCM reading is a different, interpretive exercise.

The eight principles bā gāng · 八纲

A four-pair framework for organising everything gathered in the examination: Interior / Exterior (where), Cold / Heat (which direction), Deficiency / Excess (how much reserve), Yin / Yang (the summary pair).

It is a way of sorting, not a diagnosis. Its value is that it forces the practitioner to state assumptions — which is exactly what modern clinical reasoning also demands.

Pattern differentiation biàn zhèng lùn zhì · 辨证论治

The core reasoning step of TCM: convert what was gathered at the examination into a pattern, then choose a strategy to match that pattern. The classical phrase adds 论治 — treatment follows the pattern.

Two patients with the same Western diagnosis may be given different TCM patterns and therefore different treatments. That difference is the whole basis of TCM treatment design, and also the reason it is hard to test in a standard trial format.

Why one sign is never enough dān zhēng · 为什么不能只看一个征象

A red tongue, a wiry pulse or a dislike of cold can each point in several directions. In the classical method they are weighed together, and the pattern is chosen from the combination.

This is also why "I read that a red tongue means X" is a poor way to use any TCM material — including this one. The tradition itself insists on the combination; that insistence is one of its more defensible features.

What is being assessed in a consultation píng gū · 就诊时在评估什么

Beyond tongue and pulse, a practitioner is assessing: how you respond to temperature, when symptoms appear and worsen, what improves them, sleep and appetite, bowel and urinary patterns, energy across the day, and emotional tone.

The value of asking all of this is not mysterious — it is a thorough history. Much of what is called TCM diagnosis is simply the kind of careful questioning that is good practice in any system.

Red flags that end the consultation hóng qí · 必须立刻结束问诊的红旗

Certain findings mean you should be in emergency or urgent care, not in a TCM consultation: chest pain or pressure, difficulty breathing, one-sided weakness or numbness, facial drooping, slurred speech, sudden severe headache, uncontrolled bleeding, high fever with confusion or stiff neck, severe abdominal pain, thoughts of self-harm, significant injury, pregnancy complications, or illness in an infant.

No tradition, and no practitioner, should keep treating something that belongs in an emergency department.

The ten questions shí wèn · 十问

The classical interview is organised into ten lines, remembered as a mnemonic. In outline they cover: cold and heat, sweating, the head and body, stool and urine, diet and appetite, the chest and abdomen, hearing, thirst, past illness, and the cause and course of the present complaint.

Its value is that it works as a checklist. A practitioner who runs through it will not forget sleep, appetite or bowel habit, which are exactly the everyday details patients rarely volunteer and which often carry the most information.

The five colours of the face miàn sè wǔ sè · 面色五色

Five colours are described as appearing on the face, each paired with a pattern and a system: blue-green with Liver and with cold or pain, red with Heat, yellow with Spleen and damp, white with Lung and with deficiency or cold, and dark or black with Kidney.

Two cautions apply. In classical practice a colour is always read together with the pulse and the interview, never alone. And several of these appearances, such as a yellow tinge or a grey pallor, are also signs that modern medicine treats as reasons to seek assessment.

Listening and smelling wén zhěn · 闻诊

The second of the four examinations covers what a practitioner hears and smells: the strength and tone of the voice, whether speech is low or forceful, breathing, coughing, sighing, and unusual odours of the body or breath.

The vocabulary is qualitative rather than measured: a low, weak voice is read as deficiency and a loud, coarse voice as excess. Modern readers should note that some findings in this category, notably an unusual breath odour, are also clinical signs that warrant proper medical assessment.

Abdominal examination in classical practice fù zhěn · 腹诊

Classical texts describe palpating the abdomen: its overall tension, the location of tenderness, whether pressure relieves or worsens discomfort, and whether there are palpable masses or a sense of shifting fluid.

This overlaps with what any clinician does during an abdominal examination, and the dividing line matters. Anything new, severe, or accompanied by fever, bleeding or weight loss calls for medical assessment rather than pattern reasoning.

Tongue Zones: Tip, Middle and Root shé xiàng fēn qū · 舌象分区

Classical tongue reading divides the surface into regions and reads each against a part of the body: the tip is associated with the Heart and Lung, the middle with the Spleen and Stomach, the sides with the Liver and Gallbladder, and the root with the Kidney.

The logic is a mapping, not a measurement. It tells you where to look, not what a finding means. Two practitioners looking at the same tongue can describe it identically and still weigh it differently.

Practical cautions apply to observation itself: strong coffee, tea, coloured sweets and cigarettes alter the coating within minutes, and some medications and mouthwashes change it more durably. A tongue is read in a standard light, and the observation is only one contribution to the whole assessment.

Paediatric Inspection and the Finger Vein xiǎo ér wàng zhěn yǔ zhǐ wén · 小儿望诊与指纹

Examining young children required its own classical method, because a child cannot describe symptoms reliably and will not sit still for a long pulse reading. Inspection therefore carries more weight, and specific attention is paid to the index finger.

The so-called finger vein is the small superficial vessel on the radial side of a young child index finger. Classical texts describe it in three passes and use its colour and position as one of several observations. It is a traditional marker, not a laboratory value, and its reliability is debated even within the tradition.

For parents, the useful message is the opposite of a technique: an infant or toddler who is unusually drowsy, breathing fast, feeding poorly, or running a high fever needs medical assessment, and no observation replaces that. Children deteriorate faster than adults, which is why fever in a small child is a clinical matter rather than a pattern question.

Combining the Four Examinations sì zhěn hé cān · 四诊合参

The four examinations - looking, listening and smelling, asking, and palpating - are not four separate diagnostic routes. The tradition treats them as one process, each correcting the others.

This is the answer to a question beginners ask often: why not read one strong sign and act on it? Because classical texts explicitly warn against it. A shiny red face and a fast pulse may look like heat until the asking reveals the person feels cold and wants to be covered. The signs are the same; the reading changes.

The practical consequence is that a self-check built on any single sign is unreliable by design. The tradition itself says so, which is a relief for a library that refuses to diagnose: the refusal is not caution layered on top of the method, it is what the method asks for.

Pulse Diagnosis: What Has and Has Not Been Shown mài zhěn · 脉诊：已被证实与尚未证实的部分

Pulse diagnosis is the most technically demanding part of the classical examination. Traditional texts describe dozens of pulse qualities, each with a name, a felt character and an associated pattern, and the skill is transmitted by feeling many pulses alongside a teacher.

That is also why it is hard to study. The measuring instrument is a practitioner's fingers, and studies repeatedly find only modest agreement between practitioners examining the same person - better than chance in some settings, less impressive in others. Reproducibility, not the existence of a pulse, is the open question.

Instrumented approaches exist: pressure sensors, Doppler ultrasound and smartphone-based systems have all been used to try to capture a pulse objectively. These produce numbers, but the classical categories were not defined numerically, so mapping one to the other is not straightforward.

What can be said fairly: the pulse carries real information. Rate, rhythm and the character of the arterial wall are clinically meaningful and are used in conventional medicine too. What has not been shown is that the specific classical categories can be assigned reliably and repeatably by different practitioners, or that they map onto particular conditions in the way the tradition claims. A practitioner who treats pulse findings as one input among several is being straightforward; one who treats the pulse alone as decisive is not.