XXII: Codes for special purposes

U00-U49: Provisional assignment of new diseases of uncertain etiology or emergency use

The U00-U49 code grouping in the ICD-10 represents a range of conditions and diseases that are provisionally assigned due to their uncertain etiology or for emergency use. This group includes new diseases which have not yet had their causes or transmission methods absolutely defined by the medical community. These diseases can manifest in a broad spectrum of symptoms and may affect multiple systems in the body, depending upon their nature and progression. As these condition-specific details can vary greatly and are often under study, the precise characteristics and pathologies of these diseases can be unique for each one. Due to their uncertain etiology, the exact method of transmission for these diseases may not always be known, although many are found to be communicable. The progression of these diseases is also highly variable, with some potentially developing over a long period of time while others may advance rapidly. Please refer to individual disease profiles for more specific information.