This thesis examines cognitive computing technology and how adopting it in the various areas of healthcare affects its services and procedures. Consequences from the use of cognitive technologies are studied through the objectives set in social welfare and health care reform. They are surveyed from predictive healthcare perspective. The thesis views the changes healthcare is currently facing through digitalization. The basic definition of cognitive computing is explained and it is supported with examples of processes already in use or planned in healthcare. There are also examples of research provided by the collaboration with IBM Watson. This thesis aims to offer a varied view on the development, use and application possibilities of cognitive computing and also provide a general understanding on IBM Watson technology.