We describe one approach for natural language processing and database representation of medical information. The method is based in the semantic analysis of the statements and in the identification of patterns. The processed information is indexed and structured into a frame format containing semantic slots into the database. We tested our method analysing sentences describing symptoms extracted from case reports presented in the volume 328 of the New England Journal of Medicine. The results are: 73.41% of the sentences were formatted; 81.05% of the analysed words were identified; and 95.33% of the medical terms were indexed. We conclude that this semantic approach is not only efficient for processing natural language texts, but it can also be used for the organization of medical information using a language-independent format. This interlingua that is set into the database can be applied to semantic data retrieval; serving as a basis to organize a problem-orientated medical record; displaying simultaneously the DB information into two or more languages; information interchanging among different human languages and computers; and automatic translation, among others.