Chapter XVIII
Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
(R00-R99)

This chapter includes symptoms, signs, abnormal results of clinical or other investigative procedures, and ill-defined conditions regarding which no diagnosis classifiable elsewhere is recorded.

Signs and symptoms that point rather definitely to a given diagnosis have been assigned to a category in other chapters of the classification. In general, categories in this chapter include the less well-defined conditions and symptoms that, without the necessary study of the case to establish a final diagnosis, point perhaps equally to two or more diseases or to two or more systems of the body. Practically all categories in the chapter could be designated "not otherwise specified", "unknown etiology" or "transient". The Alphabetical Index should be consulted to determine which symptoms and signs are to be allocated here and which to other chapters. The residual subcategories, numbered .8, are generally provided for other relevant symptoms that cannot be allocated elsewhere in the classification.

The conditions and signs or symptoms included in categories R00-R99 consist of:
  1. cases for which no more specific diagnosis can be made even after all the facts bearing on the case have been investigated;
  2. signs or symptoms existing at the time of initial encounter that proved to be transient and whose causes could not be determined;
  3. provisional diagnoses in a patient who failed to return for further investigation or care;
  4. cases referred elsewhere for investigation or treatment before the diagnosis was made;
  5. cases in which a more precise diagnosis was not available for any other reason;
  6. certain symptoms, for which supplementary information is provided, that represent important problems in medical care in their own right.

Excludes: abnormal findings on antenatal screening of mother ( O28.- )
certain conditions originating in the perinatal period ( P00-P96 )

This chapter contains the following blocks:
R00-R09 Symptoms and signs involving the circulatory and respiratory systems
R10-R19 Symptoms and signs involving the digestive system and abdomen
R20-R23 Symptoms and signs involving the skin and subcutaneous tissue
R25-R29 Symptoms and signs involving the nervous and musculoskeletal systems
R30-R39 Symptoms and signs involving the urinary system
R40-R46 Symptoms and signs involving cognition, perception, emotional state and behaviour
R47-R49 Symptoms and signs involving speech and voice
R50-R69 General symptoms and signs
R70-R79 Abnormal findings on examination of blood, without diagnosis
R80-R82 Abnormal findings on examination of urine, without diagnosis
R83-R89 Abnormal findings on examination of other body fluids, substances and tissues, without diagnosis
R90-R94 Abnormal findings on diagnostic imaging and in function studies, without diagnosis
R95-R99 Ill-defined and unknown causes of mortality