From Big Medical Encyclopedia

SYMPTOM (Greek symptdma coincidence, a case, a sign) — the symptom of a disease, qualitatively new, a phenomenon not inherent to a healthy organism, to-ry it is possible to find by means of clinical methods of a research, used for diagnosis and (or) the forecast of a disease. With, assumes not only emergence any new, unusual, but also lack of the normal phenomenon (e.g., absence in duodenal contents of a portion of B at cholelithiasis). Many important in a wedge, S.'s medicine are called by the names of the scientists who described them (e.g., Bekhterev, Lukin, Sitkovsky's symptoms).

At assessment the wedge, values C. define its such features as expressiveness, constancy (frequency of detection at this or these diseases), stability in relation to phases diseases (see), variability, ugrozhayemost, etc. As a rule, several features of S., however, depending on a wedge, situations are estimated at once, assessment only of one its feature sometimes matters. E.g., at the states demanding acute management, the greatest value is gained by S.'s features testimonial of threat of disturbance of the vital functions of an organism.

On a way and availability of identification of S. divide on objective and subjective, explicit and hidden; on terms of manifestation and identification — on early and late, and on diagnostic value from positions of pathogenetic interpretation — on nonspecific, specific and pathognomonic (see. Diagnosis , Semiotics ). S.'s specificity often depends on specification of its qualitative characteristic. E.g., rattles in lungs — the nonspecific S. which is found at many diseases. Specification of belonging of rattles to a class wet or dry, determination of their caliber, sonority, localization, connection with phases of breath etc. allows to establish their specificity, e.g., for pneumonia, bronchial asthma, heart failure etc. However even S., specific to a specific disease, in itself are insufficient for statement of absolutely reliable diagnosis (see); they only point to high degree of probability of the correct recognition of a disease, a cut is implemented in the presence and other its signs, i.e. set of Page. The symptoms which are observed only at one disease (e.g., crystals uric to - you in contents of tofus at gout), have absolute diagnostic value and are called pathognomonic. However pathognomonic S. are not always found at the corresponding diseases (not in all of them stages or not at all forms of a current).

For S.'s use in differential diagnosis of diseases by the COMPUTER they are determined as probabilistic, determining and ideal. Probabilistic call rather specific S., to-rye meet at one of differentiable diseases authentically more often. S. which are found only at one of differentiable diseases or appearing with the probability, by 5 times exceeding these S.' probability at other differentiable diseases are considered determining. Ideal call S. having the greatest informational content (allowing to establish existence of a disease), differentsialnodiagnostichesky value, objective expression and at the same time revealed and controlled with the smallest expense of means, time and the smallest danger and trouble to the patient of the procedure of inspection.

Association C. on the basis of their communication with etiology (see) and pathogeny (see) or only with a pathogeny (at an unspecified etiology of a disease) makes clinical expression nosology (see). Within S.'s nosology the symptom of a disease looks as external (defined clinically).

See also Syndrome .

Bibliography: Lazovskis I. R. Reference book of clinical symptoms and syndromes, M., 1981.

E. I. Sokolov, T. A. Polosova.