Health information systems are the basis of eHealth at regional and national levels. They provide the maintenance of traditional medical documents in out-patient clinics and hospitals in electronic form. At the same time, specialized registries are monitoring systems for the health status of people with certain diseases. However, the creation of registers as independent information systems, which takes place to this day, is now inadvisable, since the necessary information can be obtained from the Electronic Healthcare Record/ Electronic Medical Record. In this case, specialized registers are implemented as virtual systems of a temporary or permanent type. Regarding patient registers, they integrate data from electronic medical records and information from patients or their relatives.