In the nineties, the present author developed a didactic endothelium dysfunction classification based on personal experience while waiting for a consensus about the need of such an accomplishment. As time went by and no publications regarding this subject were released, he published a text entitled "An open discussion about endothelial dysfunction: is it timely to propose a classification? Eight years later and the question about endothelium dysfunction classification remains "an open discussion". Nevertheless, we still keep using our proposed classification although always questioning its suitability and wondering reasons for why the scientific communities avoid discussing this very subject. Based on these thoughts we attempted to hypothesize the causes of why this proposed discussion is not an inciting issue: (I) First hypothesis: An endothelium dysfunction classification is not important; (II) Second hypothesis: Such classification is still a "premature reductionism"; (III) Third hypothesis: Endothelium dysfunction is a multifaceted disorder and involves uncountable variations becoming impossible to propose an adequate classification; (IV) Fourth hypothesis: Vasoplegic syndrome and massive nitric oxide release accounts for the functional classification, thus, it seems that cardiovascular journals feel apprehensive about this since their point of view is closely associated with impaired endothelium nitric oxide release as a cause to increased risk of spasm and thrombosis and; (V) Fifth hypothesis: The classification is so fulfilling that it discards the need of discussion or the pioneer attitude to propose such classification has incited some degree of jealousy. Obviously, the fifth hypothesis is pretentiously and overwhelmed, but we again attempt to reopen this discussion because it is time to update the presented classification. In this manner, we are sure that this issue demands special attention of the scientific community. Therefore, the aim of this text is exclusively to "reopen" the discussion about the need of an effective endothelium dysfunction classification.