Diathesis

Diathesis (Gr. dia, 'through,' and tithēmi, 'I place or arrange'), a Greek word signifying a disposition or arrangement, and applied by the old medical authors to the predisposition or constitution of the body which renders it prone to certain diseased states. By recent writers the term is applied to the general constitutional tendency of an individual, to indicate not merely the class of diseases to which he is most likely to be liable, but also in many cases the manner in which his normal functions, both bodily and mental, are carried on; and is thus opposed to Cachexia (q.v.), an unhealthy condition associated with actual disease. Though the study of diathesis apart from existing disease is very apt to lead to over-refinement and the pursuit of intangible abstractions, yet a proper appreciation of a person's constitutional proclivities or diathesis often enables a medical man to advise him how to regulate his life and habits to the best advantage—what to do and what to avoid—and may furnish important guidance as to his treatment in disease. The diatheses most usually recognised are the sanguine, the nervous or neurotic, the bilious, the lymphatic, the strumous, and the hæmorrhagic. Numerous mixed varieties are also described by some writers.