This paper discusses the preliminary results of a corpus-based analysis of three basic health-related lexical items: 'disease', 'illness' and 'sickness' on the British National Corpus (henceforth BNC) CQP Web platform (2007 XML). Synonymous at first glance, the terms exhibit a certain degree of co-text and context semantic variation; therefore, the lexical items in question cannot be used interchangeably. This in turn may pose some difficulties in inter-lingual translation and language learning, mainly stemming from the lack of full equivalence (or, in some instances, zero equivalence) between the words and their counterparts in some other languages, such as German or Italian. The paper aims to demonstrate how collocational behaviour and se...