Radiotherapy occupies an important position in comprehensive cancer treatment

and radiation injury is an important bottleneck that limits its development. "Conghua" theory

which originated from

Huangdi Neijing

is an important theory of pathogenesis that summarizes the characteristic law of pathological change. Radiation has the characteristics of high speed

high energy

and high lethality

which accords with the category of "toxic pathogen" in traditional Chinese medicine. Toxic pathogen has the obvious characteristic of "conghua" .After the radiation toxin damages the body

according to the yin and yang attributes of the physical difference and invaded site

it transforms into a yang toxin or yin toxin

respectively

which may be a key link in the evolution of radiation injury. The radiation toxin invades the yin-deficient and dry-heat constitutions

or yang fu-organs and exterior sites

which are easy to change from yang to "heat-toxin"

"dryness-toxin"

and "wind-toxin" ; and it invades the yang-deficient and cold-dampness constitutions

or yin zang-organs and interior sites

which are easy to change from yin to "phlegm-toxin" and "stasis-toxin" .Therefore

in the treatment of radiation injury

it is necessary to distinguish the yin and yang bias of the constitution

the internal and external parts of the viscera

and the slow and urgent stages of the disease to identify the pathological state caused by various kinds of toxic pathogens

examine pathogenesis

and provide treatment according to syndrome differentiation. Based on the connotation of "conghua" theory and the pathogenic characteristics of radiation

this paper discusses the laws of pathological evolution and syndrome change in radiation injury

in order to provide new directions for the clinical treatment of radiation injury.