Dang Gui Si Ni Tang Granules, 100g

This formula may be regarded as a variation of Cinnamon Twig Decoction (gui zhi tang). The source text notes that it is indicated for cold injuring the terminal yin with "extremely cold hands and feet with a pulse that is thin almost to the point of being imperceptible." The use of this formula has been expanded over the centuries to encompass a variety of conditions due to cold invading the channels with underlying blood deficiency. The type of frigid extremities disorder for which this formula is indicated (due to cold in the channels and blood deficiency) can be distinguished from yin- or cold-type collapsing disorder (due to interior cold from deficiency) in that only the hands and feet are cold, as opposed to the entire limb. In addition, when the yin has collapsed the patient will also experience lethargy, an increased desire to sleep, watery diarrhea, and a submerged pulse. This requires a formula such as Frigid Extremities Decoction (si ni tang). Compared with yang- or hot-type collapsing disorder (due to constrained qi), this condition is of longer duration, the hands and feet feel colder to the patient, and the cold affects the entire hand and foot instead of just the fingers and toes. Hot-type collapsing disorder is also characterized by an aversion to heat, thirst, irritability, insomnia, constipation, dark urine, and a red tongue with a dry, yellow coating. This condition should be treated with Frigid Extremities Powder (Bai hu tang). From: Bensky: Chinese Herbal Medicine Formulas and Strategies*