Based on case observations and related data

onset

pathogenesis characteristics

as well as syndrome differentiation and treatment of coronavirus disease（COVID-19） in Human province were summarized. It is considered that the COVID-19 belongs to a unique epidemic toxin

which has characteristics of dampness

toxin and dryness. It can be defined as the epidemic toxin of "dampness-toxin and dryness"

in which "dampness-toxin"is the basis of pathology

"combination of dryness"is the pathological feature

and "illness of child organ affecting mother organ"is the thriving reason of dryness and dampness-toxin. External manifestations of dryness and dampness are lung dryness and spleen dampness

which mainly damage lung and spleen

and later on the five internal organs. According to the condition

it can be treated by stages. In the early stage

as dampness-toxin obstructing lung

and dryness damaging lung yin

the treatment should be drying dampness and relieving superficies. Meanwhile

attention should be paid to the protection of fluid and qi to avoid to excessive dryness damaging yin. In the middle stage

the epidemic toxin damages lung. Based on ventilating lung qi and detoxification

medicines clearing lung and moistening dryness should be added

and those invigorating blood and dredging collateral can be added according to the circumstances.In the extreme stage（critical illness）

the epidemic toxin congests lung

with internal blockade and external collapse. The treatment is opening blockade and relieving collapse

as well as removing toxicity and rescuing patient from collapse. We should pay attention to syndrome differentiation and treatment according to yin

yang

deficiency and excess. During the recovery stage

the pathogen still exists and healthy qi does not recover. It is necessary to use the method of clearing and supplementing

as well as diffusing internally and externally.