Although the medical practitioner should have the final say about any medical record changes, new, innovative methods which can help in the data summarization are welcome. In addition to being focused on the summarization in relation to the patient, or to the diagnosis, this proposed method and tool can be effectively used when the patient-diagnosis relation is not one-to-one but many-to-many. The proposed summarization principles were tested on a single type of the medical information system, but can easily be applied to other medical software packages, too. Depending on the existing data structure of the target system, as well as identified use cases, it is possible to extend the data and customize the proposed summarization method.