(External diagnosis is complex, with facial color, eye color, and tongue coating being the three main aspects. Here, I will focus on the critical diagnostic points related to life and death, as detailed in my work "External Diagnosis Simplified.")
Eye color reflects the state of the five zang organs, facial color reflects the six fu organs, and the tongue coating helps differentiate between external and internal conditions, cold and heat, and the vitality of blood and qi. Previous scholars separated qi and color, and further divided light and color, which is a refined theory detailed in "External Diagnosis Simplified."
Lingshu-Wuse discusses the origin and direction of facial color. Where the color originates, it is tight and deep; where it spreads, it gradually becomes lighter and sharper. Thus, it is said: "Sharp at the top indicates emptiness and upward direction; sharp at the bottom indicates downward direction." Observing where the color originates helps identify the affected zang organ, and where it spreads indicates the progression of the disease. This can be used to assess the prognosis.
When examining facial color, the initial impression upon first glance is crucial. It should be observed from both front and side angles. It is important to distinguish between coarse and dry, and between bright and moist versus floating and fiery. Generally, a dense and turbid facial color is less concerning than a thin and frail one; a full-face color is less alarming than a single line.
When examining facial color, a true color appears initially like foxtail millet, beads, or threads. It should also be observed whether the color is deeply connected to the flesh. A dull and stagnant complexion reflects qi or light. Even if it appears very dry and dark, it usually indicates illness rather than death, as the flesh still retains some moisture.
Just as there are true zang pulses, there are also true zang colors. A deep, heavy yellow color, like soil piled on the skin, around the eyebrows, eyes, cheekbones, nose, or lips, is extremely ominous.The area in front of the temples and below the ears is known as the "blessing area." Sudden dullness here indicates impending illness. Persistent dullness suggests kidney and bladder yang qi deficiency and also predicts a difficult life. Sudden brightness with a floating, fiery appearance is ominous. Gradual brightness indicates recovery from a long illness. Constant brightness signifies health and happiness. Persistent redness indicates blood aspect dryness-heat and a life of hard work and turmoil. Well-rounded temples suggest a kind and fortunate personality, while thin and drooping temples indicate cunning.
Facial color is primarily observed at the "Heaven's Center" (forehead). Red and black colors are most ominous. If colors resembling foxtail millet or beans appear, it is a bad sign. If other areas show corresponding colors, the danger is even greater. In pregnant women, redness indicates difficult childbirth. In ordinary people, both men and women, it predicts danger from weapons or fire.
Facial and eye colors should complement each other; mutual conflict is unfavorable. If the facial color supports the eye color, recovery is quick; if the eye color supports the facial color, recovery is slow. If the eye color overcomes the facial color, death is slow; if the facial color overcomes the eye color, death is swift. If a patient's condition worsens daily but their facial color becomes brighter and their eyes more spirited than usual, it is ominous.
A diffuse facial color indicates illness. If the color enters the orifices, such as the eyebrows, eyes, nostrils, or mouth, it is a sign of danger.Qianjin Fang provides detailed explanations. Colors entering the orifices mean entering the eyebrows, eyes, nostrils, or mouth. If colors appear simultaneously in two areas and gradually connect, it is ominous.
In patients with long-standing damp phlegm and heaviness, spleen dampness and liver depression often show a horizontal line of dullness below the root of the nose. If there is a slight redness within, it indicates latent heat. Although the color is deep, it is not fatal. If it extends to the eyelids and cheekbones, it is ominous.If the area around the tip of the nose and the sides of the nostrils is purplish-dark, and the tip of the nose, cheekbones, and lips appear swollen and shiny, it indicates syphilitic skin lesions in the lower body and is incurable.
If facial color starts internally and spreads outward, the internal area gradually opening indicates the dissipation of illness. Thus, even if the overall facial color is poor, a bright and deep color at the glabella, root of the nose, and tip of the nose suggests no immediate danger. If the color starts externally and moves inward, it indicates deep illness and is ominous. If it moves upward past the cheekbones or downward past the eyes, it is also ominous. Additionally,Neijing states, "For men, the left side is adverse, and the right side is favorable; for women, the right side is adverse, and the left side is favorable."
When examining the eyes, it was traditionally considered unfavorable to see the whites of the eyes (sclera). However, this is not necessarily true, as prolonged illness can cause the eyelids to thin and expose the sclera. The black of the eye (iris) is the main focus. A tightly constricted pupil with clear margins and a serene light within indicates longevity and safety even in illness. A suddenly enlarged or shrunken pupil, blurred margins, and a turbid light are all unfavorable. In newborns, a wide pupil indicates a short life. Yellow sclera suggests damp-heat; yellow iris indicates severe damp-heat or blood deficiency. A yellow iris also suggests kidney deficiency. Severe yellowing indicates jaundice, scrofula, or Yongju. Red veins crossing the pupil are incurable. Ordinary people with many red veins in the sclera are prone to major upheavals. If the forehead, eyebrows, and cheekbones show corresponding redness, it will soon manifest.
When examining the tongue, differentiate between the tongue coating and the tongue body. Even if the coating is poor, a normal tongue body indicates only stomach qi disturbance. If the coating grows from within the tongue and cannot be completely scraped off, it suggests that qi and blood are still interconnected, indicating a rooted condition.Generally, a tongue coating that is even, thin, and rooted is considered auspicious. A white and thick coating indicates dampness with heat. A coating that suddenly becomes thick or thin suggests, in mild cases, that the lung qi is active, and in severe cases, that the kidney qi is about to extinguish. A coating that is thick at the edges and thin in the middle, or absent in the middle, indicates yin deficiency or blood deficiency. A deep, narrow groove in the middle of the tongue, resembling a crack, suggests stomach atrophy. A raised tongue root with bean-like protrusions and a deep, wide groove in the middle indicates stomach stagnation. Red, raised spots on the tongue indicate stomach heat. If these spots are on the sides, they indicate liver heat; if at the tip, heart heat. Pale and sunken spots indicate stomach deficiency. In children, such spots suggest stagnation or parasites. A tongue that appears to have a coating but is completely clean upon scraping indicates blood deficiency. A thick coating, either yellow or white, resembling wet powder, that does not gradually thin out towards the edges, indicates stomach exhaustion.
Black tongue coating indicates blood stasis. Gray tongue coating indicates blood stasis accompanied by phlegm and fluid. Women with cold-damage disease or seasonal disease are most prone to developing black tongue coating, which should not be hastily considered as a bad sign. Traditional methods differentiate cold and heat based on the presence of prickles, dryness, or moistness and fineness of the black coating. In cases of static blood, although the tongue coating is black and there is internal heat, prickles do not immediately appear. People with cigarette addiction tend to have dry and prickly tongue coatings, but this does not necessarily indicate true internal heat; it may simply be due to damage to the lung and stomach fluids. Whenever gray or black tongue coatings are observed, it is generally advisable to also promote blood circulation. If the symptoms of cold or heat are severe, unconsciousness or delirious speech is likely; if there is no cold or heat, there is likely a lump of heat in the chest and ribs, causing internal restlessness and sleeplessness at night. If the tongue is stiff and contracted, speech is impaired, or the body is heavy and unable to turn, or one side cannot sleep, these are ominous signs.
A dry, dull tongue with prickles indicates extreme blood dryness-heat. Even if a black crust forms, there is still a chance of survival, but if the tongue is smooth and mirror-like, it is ominous. Some healthy individuals may have cold phlegm or static blood in the stomach, often showing a smooth, mirror-like patch on the tongue, which should be carefully inquired about during diagnosis. Also, those with abdominal masses or heart and stomach qi pain often exhibit strange tongue coatings during illness, especially in gynecological cases.
In chronic illnesses, teeth that are shiny and free of plaque are ominous. Teeth that are dry and yellow, appearing as if coated but not, or those that have a coating that can be brushed off completely, indicate that kidney qi is nearly exhausted. Lips that are pale and lack luster are also a bad sign. A full philtrum that is wide and lacks ridges, or lips that curl downward like a bow, are also ominous. When examining the ears, they should match the color of the face and eyes. If they do not, observe their condition and determine the prognosis based on their appearance. Ears that suddenly become dry and dusty are ominous. However, healthy individuals with a pale and moist complexion but constantly dark and not dry ear rims may actually have robust kidney qi.
If the body is thin and the muscles and bones are tightly attached, and the skin and flesh are tightly connected, or if the skin is dry and flaky but not cracked or raised like foxtail millet, there is no need to worry. However, if the muscles and bones are separated, the skin and flesh are loose, and the skin feels like hemp or beans to the touch, or if the body is hot without sweat but there is sweat on the back, heart cavity, forehead, or nose bridge, or if the bones behind the thumb and index finger are exposed, or if the area around the eyelids is deeply sunken, or if the large tendon at the back of the neck is deeply sunken like a pit, these are all serious signs. The sides of the large tendon being sunken is normal, but if the center is not sunken, it is not a problem. It is acceptable for muscles and fat to be thin, but it is not acceptable for the sinews and interstices to be dry, shrunken, or slack. The body is nourished by blood, and the color is produced by blood. In severe illness, the blood becomes turbid, and in prolonged illness, blood deficiency occurs, leading to corresponding changes in form and color. If the blood is disordered, scattered, dry, or dead, the form and color will not correspond, indicating an abnormal change.