How does a TCM physician diagnose disease?

PHOTO: How does a TCM physician diagnose disease?

A TCM physician’s inspection of a patient can be divided into four stages, commonly known the Four Examinations (si zhen).

They are Looking, Listening and Smelling, Inquiring and Touching. Together, these methods aim to provide an objective basis for diagnosing the patient’s condition.

1. Looking

There are four characteristics that are visible to the naked eye. First is the general appearance – the patient’s physical shape, manner, and the way he behaves during the Examination. All these are indications of his health. For example, a patient with severe back pain is usually unable to move easily. Overall, the physician will observe the patient’s demeanor, movement, voice, bodily sounds and complexion.

The second characteristic is facial color. According to the TCM Five Elements Theory, the Five Elements (Wood, Fire, Earth, Metal and Water) are linked with five organs and each organ has a specific color. Red links with the heart, Yellow links with the Spleen, White links with the lungs, Green connects with Liver and Black is the color of kidneys. Based on this understanding, a person’s appearance is a reflection of his internal state of health. A patient who is suffering from ‘Heat’ or ‘Excess’ disease may have a red complexion. On the other hand, a weak-looking, frail individual is more likely to be suffering from ‘Cold’ or ‘deficient’ disease.

The third requires an examination of the tongue - its shape, coating and movement. The tongue reveals the basic qualities of a person’s state of health. A normal tongue is pale red and somewhat moist. The healthy color is the result of smoothly moving Qi. If the tongue maintains its normal color during an illness, it is a sign that the Qi and Blood have not been affected, and the prognosis is very favorable.

A pale tongue indicates Deficient Blood, Deficient Qi or Excess Cold. A red tongue points to a Heat condition in a body, while a tongue with a dark tinge signifies some form of stagnation.

The tongue material and tongue moss or “fur” are treated as two separate elements. The coating, fur, or moss on the surface of the tongue is the result of Spleen activity.  A thin moss can be normal, but during an illness it may be a sign of Deficiency. A very thick moss is nearly always a sign of Excess. Moss that is puddled with moisture is a sign of Excess Fluids, usually due to Deficient Yang and/or a possible sign of Dampness.

A moss that appears firmly implanted on the tongue body, like grass sprouting from the ground, signifies strong Spleen and Stomach Qi. Moss that appears to be floating on the surface of the tongue is a sign of weak Spleen and Stomach Qi.

Yellow moss points to Heat: the deeper the yellow, the greater the Heat. Black or gray moss is a sign of either extreme Heat or Cold - extreme Heat if the tongue material is red, extreme Cold if it is pale.

Listening, smelling, inquiring, touching

2. Listening and Smelling

First, the physician must pay attention to the patient’s voice and respiration. Coarse, strong respiration may signify Excess. Weak respiration or shortness of breath, accompanied by weak, low voice and little speech, suggests Deficiency. Wheezing most often suggests Mucus.

The TCM physician also distinguishes between two main kinds of bodily odors that are present during illness. These smells are difficult to describe, and so the physician relies heavily on experience when interpreting them.

One odor is characterised as foul, rotten, and nauseating, like the odour of rancid meat or rotten eggs. Such an odor signifies Heat. The second odor is less nauseating but more pungent or “fishy”. It is like the smell of fumes from bleach, and indicates Cold and Deficiency.

3. Inquiring

In the third of the Four Examinations, the physician asks questions to discover important but not readily apparent information. These cover the following topics: sensations of cold or hot; perspiration; headaches and dizziness; characteristics and location of pain; urination and stool; appetite and tastes; sleep and medical history. For a female patient, the physician would ask about gynecological matters.

Abnormalities in any of the abovementioned signifies disharmony of a particular organ or many organs. For instance, frequent and excessive urination could mean deficiency of the kidneys and gallbladder.

4. Touching

This involves feeling the pulse, a procedure far more complex than what we know of in modern Western medicine. Pulse taking is a subtle and complex art; when the physician takes a pulse, he is alert to a tremendous array of sensations that must be expertly understood and arranged as a unity – the “feel” of an individual pulse.

There are twenty-eight types of basic pulses. Disharmonies in the body leave a clear imprint on the pulse.

Both physician and the patient must be relaxed while feeling the pulse. 

Ms Tay Ai Choo is a certified TCM physician and a member of the Editorial Board of TCM 24. Readers may direct their queries/comments to or visit for more information.