We expose a method for extracting hyponyms and hypernyms from analytical definitions, focusing on the relation observed between hypernyms and relational adjectives (e.g., cardiovascular diffease). These adjectives intro-duce a set of specialized features according to a categorization proper to a par-ticular knowledge domain. For detecting these sequences of hypernyms associ-ated to relational adjectives, we perform a set of linguistic heuristics for recog-nizing such adjectives from others (e.g. psychological/ugly disorder). In our case, we applied linguistic heuristics for identifying such sequences from medi-cal texts in Spanish. The use of these heuristics allows a trade-off between pre-cision & recall, which is an important advance that complements other works.