The drug name of chestnut shell is Chestnut Hairball, and its effects are to dissolve phlegm, disperse knots, and detoxify toxins. It is used in the treatment of dengtoxin (an acute infection in which the skin is red like paint), scrofula (mainly refers to tuberculosis of the lymph nodes in the neck), phlegm nuclei (lumps swollen under the skin like nuclei), and other diseases. Chestnut Hairball is a kind of traditional Chinese medicine with sweet, astringent flavor and flat nature, which belongs to the heart and lung meridians, and is the involucre of chestnut. It is effective in resolving phlegm, dispersing lumps and detoxifying. It is usually decocted and used externally when used for dengtoxin and swelling toxin under Chinese medicine diagnosis, and usually decocted and used internally when treating scrofula, phlegm nuclei and whooping cough. The adverse reactions, contraindications and precautions of this product are not clear. Chestnut shells are not commonly used in clinical Chinese medicine, it is recommended to use under the guidance of a professional Chinese medicine practitioner, individuals should not use blindly, so as not to cause adverse effects.