The endotype is an independent disease entity that can occur in a group of phenotypes. It is defined by a specific functional or pathobiological mechanism. An example of this is asthma, which is considered a syndrome consisting of a number of endotypes.
This distinguishes it from a phenotype.
The phenotype is an observable characteristic or a specific feature of a disease. The phenotype does not refer to a disease process, including its pathophysiology or to triggers and inflammatory parameters. It results from the interactions between genotype and environment.