Big data analysis is changing the world of healthcare. Its potential has yet to be fully realized, but includes medical diagnosis, epidemic prediction, gauging public response to government health warnings, and the reduction in costs. ‘Big data and medicine’ considers healthcare informatics, which uses big data to provide improved patient care and reduce costs. Mining social media data for public health related research is now a recognized practice within the academic community. Google Flu Trends is discussed along with the Watson medical system, which retrieves and analyses structured and unstructured data. Big data use in healthcare evidently has great potential, but what about the privacy of the individual’s medical data?