Chinese Herbal Medicine: Actions, Combinations and Safety
Core framework
Candidates must be able to place every herb within four coordinates: nature and flavour (temperature, taste, channel entry), category and primary action, classical combination partners, and contraindications/cautions. Questions frequently test the pair, not the single herb - for example, the logic of combining a warming disperser with a cooling one to prevent over-heating, or an astringent with a qi-mover to prevent stagnation. Learn representative herbs per category (release exterior, clear heat, drain dampness, transform phlegm, regulate qi, invigorate blood, tonify qi/blood/yin/yang, astringe) plus two or three classic dui yao for each.
Traps to expect
- Name confusion - herbs with similar pinyin or shared characters but different actions (e.g. tonifying versus draining herbs with near-identical names).
- Flavour–action mismatch - assuming all bitter herbs drain heat; some bitter herbs dry dampness without clearing fire.
- Processing (pao zhi) - honey-frying, wine-frying, salt-frying and charring change direction and strength; a question may hinge on the processed rather than raw form.
- Safety specifics - toxic herbs requiring prolonged decoction or strict dose ceilings, herbs contraindicated in pregnancy, and herbs that must not be combined with specific western drugs or with each other (the classical shi ba fan and shi jiu wei lists).
- Dose and duration - short courses for dispersing or harsh herbs; longer for tonics; never assume "more is stronger".
Worked example
A question describes a patient with cold, deficient middle jiao and asks which addition prevents cloying stagnation when a rich qi tonic is prescribed. Rule of thumb: whenever a supplementing herb is heavy or cloying, pair it with a gentle qi-mover or damp-drainer; when a dispersing herb is drying, pair it with a yin-nourishing or fluid-preserving herb. Apply this "balance the side-effect" logic before memorised pair lists - it resolves most combination items even when the exact herb pair is unfamiliar.