张登

Zhang Deng's life and career are unknown, and publicly available information is limited: at present, he is known only as the author of one medical work, Shanghan Shejian (A Mirror of the Tongue in Cold Damage Disorders). This book is a specialized treatise on tongue diagnosis in traditional Chinese medicine. It discusses changes in the tongue in cold damage disorders, relating features such as the tongue coating and tongue body to pathogenesis and pattern differentiation for clinical reference. Judging from the surviving evidence, Zhang Deng's writing is practical in orientation, focusing on the correspondence between tongue signs and patterns, with the text serving diagnostic judgment rather than elaborate discussion of medical theory. A specialized work of modest length, it gathers diagnostic experience in concentrated form, allowing readers to consult it alongside their study of cold damage disorders and inspection diagnosis. Because biographical records are lacking, his medical training, associations, and sphere of influence cannot be verified; his contribution can be understood only through the subject matter and organization of this work, which offers later readers a readable source for understanding how earlier physicians used tongue signs to aid pattern differentiation.