Fog and haze affect the human body in many ways

and discussion of the characteristics of fog and haze causing diseases has the practical significance. This article reviews the knowledge of ancient people and the recent research for fog and haze. Based on the cardio-pulmonary function harm and clinical manifestation induced by fog and haze

the authors believe that fog and haze belong to exogenous pathogenic factors

and have the characteristics of exogenous pathogenic factor causing diseases. Fog and haze are unique"mai-toxin"

which is different from six climatic pathogens and the pestilence. When diagnosing and treating the diseases caused by fog and haze

the physicians should pay attention to the etiology and pathogenesis

and used the new technology for clinical basis.