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The tongue coating is thin and white, covering the tongue like rice gruel; this is an initial manifestation of Cold Damage (Shanghan) or Middle Cold (Zhonghan). If no exterior syndrome symptoms are present, it indicates food stagnation in the upper chest and diaphragm.

The tongue coating is white and covers the tongue like soy milk; this refers to a white and slippery coating, seen in diseases such as Cold Damage, Middle Cold, Dampness pathogen, and Phlegm-fluid retention. These should be differentiated and diagnosed via pulse examination. However, if the coating is thin and white without moisture, and the tongue body is not very red, it indicates an exterior syndrome caused by Dryness injury.

The tongue coating is white, thick, and dense, spreading over the tongue like tofu brain; this is a Phlegm-Heat syndrome.

The tongue coating is white and sparse, resembling rice flour spread on a red surface; this is an initial transmission stage of Heat injury or Summerheat injury.

The tongue coating is white like millet grains forming granules; this indicates the Heat pathogen is in the Qi level.

The tongue coating is white like silver, meaning bright and shiny like silver; this is a transformed coating resulting from the mistaken use of tonification in a Heat syndrome.

The tongue coating is white like the gray color of dried tobacco; regardless of whether it is moist or dry, this is a transformed coating resulting from the mistaken use of drying agents in a Heat syndrome.

The tongue coating is white like the bottom of a silver ingot, meaning it has holes similar to the pattern of a silver ingot's base; this indicates that in a Heat syndrome, due to mistaken use of both tonification and drying methods, the Body Fluids have been damaged, the Original Qi is about to sink, and the pathogenic factor is about to penetrate deeply.

The tongue coating is white like tofu dregs piled on the tongue; this indicates that in a Heat syndrome, due to the mistaken use of drying methods, putrid turbidity has accumulated in the Stomach, and a Interior Excess syndrome is about to develop. If there is a crack in the center, it indicates a condition of extreme deficiency mimicking excess; one should tonify Qi, but differentiation must be made via pulse examination.

The tongue coating is white like tofu fibers piled on the tongue, meaning the white coating is thick with holes, resembling cooked tofu with pores; if there are two or three strips of white while the rest is red, or if the coating feels rough like sandpaper, this indicates that Dryness has damaged the Stomach fluids, preventing them from moistening the tongue, and Kidney Qi cannot ascend. There may also be cases where Clear Qi is suppressed and unable to generate fluids; these should be differentiated and diagnosed via pulse examination. Refer to the section on yellow and black coatings like pot scorch for comparison.

The coating appears white but is not truly white, resembling snow-blue created by painters mixing powder with grease. There are two depths: light snow-blue resembles the color of lake crepe, indicating the initial entry of Heat pathogen into the Ying (Nutritive) level; deep snow-blue resembles the color of Hang silk, indicating that Summerheat and Heat pathogens have entered the Xue (Blood) level.

This coating resembles thin white, but the tongue body is red, and upon close inspection, tiny papillae points are visible, hence named "snow-blue." This is a mandatory coating for Blood-level Heat syndromes. It is often difficult for later students to comprehend; therefore, careful observation and proportional analogy are used to explain directly, to avoid misdiagnosis.

The tongue body is deep red, resembling dried carrot sticks with salt frost; this indicates that Heat pathogen has penetrated deeply and lingered for a long time, and the mistaken use of purgative and drying drugs has severely damaged Stomach Yin. This is a critical stage at the end of Warm-Heat disease transmission.