Organic and functional are different in terms of lesion nature, diagnosis and treatment. 1. Nature of lesions: Organic refers to the organs and tissues have substantial damage and changes, such as inflammation, necrosis, tumors, etc. Functional refers to the organs and tissues themselves do not have substantial changes in tissue structure, only organ function abnormalities. Functionality refers to the organs and tissues themselves have no substantial changes in organization and structure, only organ function abnormalities, mostly caused by neurological dysfunction. 2. Diagnosis: Organic changes can be found through imaging, pathology and other examinations, combined with clinical manifestations and examination results for diagnosis. Functional lesions are mostly negative in imaging and pathologic examinations, and only positive changes exist in functional experiments. Functional changes should be diagnosed by exclusion, and the diagnosis of functional changes should be considered only after the exclusion of organic lesions. 3. Treatment: Organic changes are mostly irreversible changes, and some irreversible damage will remain after treatment or cure. Functional mostly reversible damage, but most of them are difficult to treat, and the condition is easy to repeat. Organic and functional are two opposing descriptions of the disease, which are mainly used to describe the nature of the lesion and guide further examination, diagnosis and treatment.