Prior to menstruation, the body's blood is programmed to flush the Conception and Thoroughfare Vessels. In general before menstruation, the uneven blood distribution inside the body deteriorates kidney and liver functions as well as that of other organs. Accumulated evils (mainly led by fire evils) take advantage of the situation to cause various pathological changes, which are responsible for the symptoms observed in PMS. After menstruation, when the body's blood redistributes and the organs resume their normal functions, the body regains its power to check the excessive evils and the PMS symptoms gradually disappear. PMS is cyclical in nature as the process starts again when the Conception and Thoroughfare Vessels become flushed with blood before the next menses.
As mentioned, symptoms of PMS vary from woman to woman and cycle to cycle. The more debilitating symptoms are differentiated according to major complaints and associated syndrome patterns.
Table (1) summarizes commonly seen PMS complaints and their associated deficiency patterns from a TCM perspective.