Large volumes of structured, unstructured, and semi-structured data have been produced in recent years by numerous global institutions; this heterogeneous data is collectively known as big data. Because several sources are known to provide large volumes of heterogeneous data, the health industry sector has to deal with the challenge of managing big data. In the healthcare industry, numerous big-data analytics technologies and approaches have been created to manage these enormous volumes of data. The influence of big data on healthcare, as well as the range of applications and technologies available within the Hadoop ecosystem, will all be covered in this paper. The fragmentation of healthcare data, ethical concerns, usability challenges, security and privacy concerns, and other issues are some of the barriers preventing the successful application of big data in healthcare, according to this research.