At the moment, I'm still at the introduction, and more precisely at the 'Medicine and the Human Condition' section. I'll quote part of it here because it is simply too interesting in terms of immersive role-playing:
The numerous medical conditions mentioned in the text constitute a health profile of a cross-section of the rural population of ancient China. The most common ailments are swellings of every kind, from the superficial to the fatal, both epidermal and organic. The organs most affected by disease are the stomach and heart, and the bodily parts most affected are the eye and skin. General ailments are piles, rheumatics, fever, choking, shortness of breath, itching, worms, chapped skin, and pains in the chest and belly. Preventive remedies are prescribed for sunstroke, risk of premature death, starvation, physical exhaustion, and epidemics. Social problems include farting and smelly armpits. Mental problems, such as stupidity, amnesia, nightmares, and nodding off are also treated. Psychological disabilities include various phobias (especially fear of thunder), depression, and acute anxiety. The sexual problems for which remedies are given include the need for contraceptives and treatment for infertility. The remedy for sexual jealousy is to eat a hermaphroditic animal, which is also good for carbuncles. [...] In prescribing treatment, the traveller-medic is careful to note any word-magic that might apply to the case. For example, a patient will not be lost or confused (mí) if he or she wears some lost-mulberry (mìgǔ) in the belt. Colour symbolism is also a function of treatment. If a patient eats a scarlet mountain fowl, it will prevent fire. Preventive medicine also extends to personal situations, such as misfortune and bad luck, which is sometimes caused by the workings of the dreaded gǔ, a term that covers malign forces, poison, and internal worms.
PS— gǔ sorcery is described in gaming terms on p89 of The Celestial Empire.