This invention relates to a method of using medical data related to patients suffering a given disease, comprising: a phase of gathering (6) medical data related to patients suffering said given disease, from different hospital databases (65 to 68) storing under different data formats said medical data within non-anonymized files, a phase of storing, in a big data database (1), said gathered medical data, anonymized and in a single standardized format, a phase of using (7, 8) said big data database (1): by performing big data processing functions (21, 22) as well as by performing simple raw data extraction (23) from said big data database and direct visualization (24) of said extracted raw data, to generate one or more global rules governing categories of patients suffering said given disease as well as to improve personal medical care for a specific patient suffering said given disease.