Pathology

The most important distinction with oedema, as with all other diseases, is that between Full type
and Empty type. Oedema of the Full type, also called Yang oedema, derives from external
Wind-Water, external Dampness or Fire-Poison. Oedema of the Empty type, also called Yin
oedema, arises from a deficiency of the Spleen and/or Kidneys.

The three Yin organs most involved in oedema are the Lungs, Spleen and Kidneys as these are
the three organs responsible for dispersing, transforming, transporting and excreting fluids. Of
the other organs, the Triple Burner plays an important role in the metabolism of fluids. The
Upper Burner diffuses fluids, like a fine spray, to the space between skin and muscles, the
Middle Burner transforms fluids and sends turbid fluids downward and the Lower Burner further
transforms and excretes fluids.

Yang oedema may develop into Yin oedema and vice versa. For example, after a long period
Yang oedema may be transformed into Yin oedema because the retained fluids impair the Spleen
and Kidneys. On the other hand, after repeated invasions of external Dampness Yin oedema may
turn into Yang oedema.

In any case, whether it is Yang or Yin oedema, it is important to remember that oedema in itself
is a Full condition, or the Full aspect of a condition. For example, although Yin oedema derives
from a deficiency of the Spleen and/or Kidneys, the fluids retained in the form of oedema are the
Full aspect of the condition. Thus, in this example, the Root of the condition is characterized by
Emptiness of Spleen and/or Kidneys, while the Manifestation is characterized by Fullness in the
form of oedema. This has important implications in treatment as oedema, as a Manifestation,
calls for draining with herbs which resolve oedema, or by reducing acupuncture points which
resolve oedema.

From a diagnostic point of view, Yin oedema is characterized by marked pitting on pressure,
with the skin being very slow to bounce back to normal. In Yang oedema there is little or no
pitting on pressure.

Differentiation and Treatment

As a general principle, oedema of the upper part of the body is treated by diaphoresis, while
oedema of the lower part is treated by diuresis.

Thus to treat oedema of the upper part of the body one uses some herbs which expel Wind, such
as Ma Huang Herba Ephedrae, Fang Feng Radix Ledebouriellae sesloidis, Fu Ping Herba