Factors which may trigger the upwards movement of rebellious Qi and Phlegm are weather
changes, diet, emotional stress and overwork.

Phlegm may be cold or hot. Cold Phlegm may derive from frequent exposure to cold which
injures the Lungs or from excessive consumption of cold foods which injure Spleen-Yang. Cold
Phlegm is more likely to be stirred by external pathogenic factors. It both derives from and
causes Yang deficiency.

Hot Phlegm may derive from excessive consuption of sour, sweet, or greasy foods. Yin
deficiency may contribute to forming Phlegm-Heat.

In chronic cases Cold Phlegm injures Spleen-Yang while Hot Phlegm injures Lung-Yin. The
disease becomes therefore characterized by a combination of Fullness (Phlegm) and Emptiness
(of the Lungs, Spleen or Kidneys). Deficient Lungs, Spleen and Kidney may in turn all lead to
Phlegm. In particular, if Kidney-Yang is deficient there will be Cold Phlegm; if Kidney-Yin is
deficient there will be Phlegm-Heat.

In severe and prolonged cases, when the deficient Lungs fail to control the blood vessels and
harmonize the channels, Heart-Blood cannot circulate properly, the Fire of the Gate of Vitality
cannot rise to the Heart and this causes a deficiency of Heart-Yang.

Differentiation and Treatment

In order to apply the correct principle of treatment a clear distinction must be made between the
acute and chronic phases. In general one follows the principle of treating the Manifestation
during the acute phase, and the Root during the chronic phase. This means that in the acute phase
one must expel pathogenic factors, resolve Phlegm and restore the descending of Lung-Qi.
During the chronic phase attention should be turned to tonifying the body's Qi, particularly of the
Lungs, Spleen or Kidneys.

In some chronic cases, it may be necessary to treat both Manifestation and Root simultaneously.

The patterns discussed are:

ACUTE PHASE

Cold Phlegm

Hot Phlegm