一、看苔色。（详后）。
二、看舌质。（质亦有色，又有大小湿热之症，舌质胀大，满口边有齿印。血热之症质色紫）。
三、看舌尖。（白苔满舌，尖有红刺，勿用温燥之药）。
四、看舌心。（四边有苔，中无，或中有直裂，或有直槽或横裂）。
五、看燥润。（以手摸之，或滑润或燥刺棘手，有看似润而摸之燥者，有看似燥而摸之滑者）。
六、看舌边。（苔色与边齐否）。
七、看舌根。（根后有无苔色接续，有无大肉瘤）。
八、看变换。（观其变与不变）。
黄色有深浅老嫩之殊，其形似亦有燥润滑涩之异。有正黄
色者；有老黄色者；有黄如炒枳壳色者；有黄黑相间如锅焦黄色者；有嫩黄色者；有牙黄色
者；有如裱心纸兼灰青色者；有黄如粟米染着者；有黄如虎斑纹者；有黄如黄蜡敷舌上者；
有水黄苔如鸡子黄白相兼染成者；有黄腐苔如豆渣炒黄堆舌者；此皆黄色之类，而症候之殊详
后。
白苔有浓薄密疏之殊，其形似亦有深浅间杂之异。有薄白如米饮敷舌者；有白如
豆浆敷舌者；有白而浓如豆腐脑铺舌者；有白而疏如米粉铺红者；有白如粟米成颗粒者；有白如银色者；有
白如旱烟灰色者；有白如银锭底者；有白如豆腐渣堆舌者；有白如豆腐筋堆舌者；有白如
糙石糙手者；有似白非白色如画工以脂调粉（此色有二∶一淡如雪青湖绉色者，一深如雪青
杭绸色者，古皆以绛色名之）。更有舌质深红如红萝卜干有盐霜者，此皆白苔之类，而寒热之症各
殊，亦细详于后。
1. Observe the color of the tongue coating (detailed discussion follows).
2. Observe the state of the tongue body (the tongue body also has color variations and is associated with conditions such as enlargement, damp-heat, etc. If the tongue body is swollen with teeth marks along the edges, it indicates this category; blood heat conditions present with a purplish tongue body).
3. Observe the tip of the tongue (if white coating covers the entire tongue but red prickles are present at the tip, avoid using warm-drying herbs).
4. Observe the center of the tongue (coating present on the sides but absent in the center, or vertical cracks, grooves, or horizontal cracks in the center).
5. Observe the dryness and moisture of the tongue surface (touch with hand to feel if it is slippery/moist or dry/prickly. Some appear moist but feel dry to the touch, while others appear dry but feel slippery).
6. Observe the sides of the tongue (check if the coating color aligns evenly with the tongue edges).
7. Observe the root of the tongue (check for continuity of coating behind the root and presence of large fleshy tumors).
8. Observe changes in the tongue image (observe whether the tongue presentation changes or remains static).
Yellow tongue coatings vary in depth and freshness (maturity), and their morphology differs in dryness, lubricity, and roughness. There are pure yellow ones; old/deep yellow ones; yellow like fried Zhiqiao Cortex Aurantii Fructus (Bitter Orange Peel); yellow-black intermixed resembling scorched pot bottom; tender/light yellow ones; tooth-yellow ones; resembling mounting paper mixed with gray-green; yellow like dyed millet grains; tiger-stripe patterned yellow; yellow like wax applied to the tongue; water-like yellow coating resembling mixed egg yolk and white; rotting/fatty coating resembling fried bean dregs piled on the tongue. These all belong to the category of yellow coatings, while the corresponding clinical manifestations are detailed later.
White tongue coatings vary in density and sparseness, and their morphology differs in depth and intermixing. There are thin white ones resembling rice water spread on the tongue; white like soy milk spread on the tongue; thick and dense white like tofu pudding spread on the tongue; sparse white like rice flour spread on a red background; white forming granules like millet grains; silver-white; gray-white like dried tobacco smoke; white like the bottom of a silver ingot; white like piled tofu dregs; white like piled tofu fibers; rough white like coarse stone that feels abrasive to the touch; and semi-white resembling paint mixed with powder by an artist (this color has two variants: one pale like snow-blue lake silk crepe, one deep like snow-blue Hangzhou silk satin; historically both were referred to as Jiang color/crimson). Furthermore, there are cases where the tongue body is deeply red like dried carrots with salt frost. All these belong to the category of white coatings, while the distinct cold and heat syndromes are detailed subsequently.