Exterior-releasing medicinal is a category of medicinals that has the effect of dispelling an external pathogen from the exterior aspect of the body, usually through sweating. Heat-clearing medicinals have the effect of clearing up internal heat in cases of externally contracted febrile diseases or fever due to yin deficiency.

There are mainly two subgroups under this category: wind-cold-dispersing medicinal* and wind-heat-dispersing medicinal*.

Wind-cold-dispersing medicinals have the effect of dispersing wind and cold in the treatment of an exterior syndrome. Most of them are pungent warm exterior-releasing medicinals* because they are pungent in flavor and warm in property. Medicinal Ephedrae and Ramulus Cinnamomi are frequently used medicinals in this category.

Medicinal Ephedrae (Ephedra* in English and mahuang in pinyin) is pungent (acrid), slightly bitter in flavor, and warm in nature. It enters lung and bladder meridians and has the actions of inducing sweating and releasing the exterior. Therefore, it is usually applied to exterior excess cold pattern (with no sweating).

Ramulus Cinnamomi (Cinnamon twig, cassia twig*). Species*: cinnamomum cassia. Pinyin: gui zhi. Common name: cinnamon twig. Quality: pungent (acrid), sweet, warm. Meridians: heart, lung, bladder. Actions: induces sweating, warms and unblocks channels, unblocks yang qi of the chest, treats dysmenorrhea.

Wind-heat-dispersing medicinal has the effect of dispersing wind and heat in the treatment of an exterior syndrome. Most of these medicinals are pungent cool exterior-releasing medicinals* as they are pungent in flavor and cool in nature.

Bohe (Medicinal Menthae), for example, grow in all parts of China but the best ones are in Jiangsu province. The medicinal material is collected in summer and autumn, and dried in the shade. This medicinal is pungent in flavor, cool in nature and enters the lung and liver meridians, which can expel wind-heat, clear heat from the head and eye, ease the throat, promote eruption, and soothe the liver and regulate qi.* Thus, this medicinal is often applied together with jingjie (Medicinala Schizonepetae) for the treatment of exterior syndrome caused by wind-heat pathogen. For the syndrome of wind and heat attacking upwards manifested as headache and redness of eyes, swollen and painful throat, bohe is usually employed together with sangye (Folium Mori) or juhua (Flos Chrysanthemi), because they can clear the heat from the head and eye.

Bohe is often used together with chantui (Periostracum Cicadae), jingjie (Medicinala Schizonepetae), and niubangzi (Fructus Arctii) to treat urticaria and rubella. Bohe can also be used to treat liver depression and qi stagnation when it is used together with chaihu (Radix Bupleuri), baishaoyao (Radix Paeoniae Alba) and danggui (Radix Angelicae Sinensis), such as xiaoyao san (powder).

3-6g is recommended in a formula used in decoction; decoct it later than the other medicinals of the formula for shorter boiling.

Chaihu (Radix Bupleuri, Bupleurnum in English) is another pungent cool exterior releasing medicinal. Property: bitter, pungent (acrid) and cool. Meridians: gallbladder, liver, pericardium and triple energizers. Actions: treats alternating chills and fever, clears lesser yang disorders, relieves liver qi stagnation, raises yang qi, and treats certain menstrual disorders.

Fig. 15-3 Five basic types of heat-clearing medicinals

There are five basic types of heat-clearing medicinals (Fig. 15-3). heat-clearing and fire-purging medicinals* are heat-clearing medicinals that have the effect of clearing heat or purging fire from the interior, such as shigao (Gypsum Fibrosum) and zhimu (Rhizoma Anemarrhenae).

Heat-clearing and dampness-drying medicinal* is another type that is effective for eliminating heat and dampness. Huangqin (Radix Scutellariae) and huanglian (Rhizoma Coptidis), for example, are of this type. Heat-clearing and detoxicating medicinal* counteracts heat toxins. Jinyinhua (Flos Lonicerae) is one of this type and is sweet in flavor, cold in nature and enters the lung, heart and stomach meridians. Heat-clearing and blood-cooling medicinal* has the effect of eliminating pathogenic heat from the nutrient and blood aspects in cases of externally contracted febrile diseases. Shengdi (radix rehmanniae) is a typical one of this kind. Deficiency heat-clearing medicinal* clears heat from deficiency conditions. Qinghao (Medicinala Artemisiae Annuae) is under this category. It is bitter and pungent in flavor, cold in nature and enters the liver, gallbladder and kidney meridians. Therefore, it is usually applied to fever due to yin deficiency, and is especially effective for tidal fever with sweating.