Functional Disease

Definition of Functional Disease

One which prevents, obstructs, or interferes with the due performance of its special functions by any organ of the body, without anatomical defect or abnormality in the organ itself. Distinguished from "organic” disease, which is due to some injury to, or lesion or malformation in, the organ in question.

That's the definition of Functional Disease in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.