Every piece of information learned in human health has the potential to improve the length and quality of life for patients. However, the search for more knowledge in the domain of Health Informatics has led to vast quantities of data, far more than can be easily processed by researchers. Fortunately, Justas this problem of Big Data has begun to challenge advances in Health Informatics, so too can the data mining and machine learning techniques used for the general study of Big Data be brought to bear on the these problems. This paper will discuss recent studies done on Big Data Analytics in the field of Health Informatics which sought to answer various clinical questions, using data acquired from the molecular, tissue, and patient levels of Health Informatics. We also consider what work remains to be done in this area.