Woodblock illustration from Shejian bianzheng (Pattern Differentiation in Tongue Examination), a Chinese manual of tongue diagnosis, published in 1905 (31st year of the Guangxu reign period of the Qing dynasty) -- simple line drawing, showing the features of the tongue morphology known as baitai xiantian hongshe (red tongue with white coating and stringy mucus). The body of the tongue is pale red with a thin, slimy white coating on the central part. This is a sign that malign qi (xieqi) has penetrated the interior of the body. The patient may exhibit symptoms such as heat in dantian (the Cinnabar Field), tightness in the chest and shortness of breath. This is a semi-external semi-internal shaoyang syndrome, which can be treated with Minor Bupleurum decoction (xiao chaihu tang) or decoction of Cape jasmine and fermented soybean (zhizi chi tang). This tongue morphology is found in the context of an internal syndrome (in this case, the white coating can easily be scraped away), where cold is congealed in the spleen and stomach. This is treated with centre-regulating decoction (lizhong tang).
