 As only one in ten cases of EIPH have epistaxis (bleeding from the nostrils), and as epistaxis can have causes other than EIPH, various diagnostic tools are used to diagnose EIPH.EIPH is most commonly diagnosed by endoscopic examination of the trachea and larger bronchi, with the optimal timing for endoscopy being 60–90 minutes after hard exercise.This post-exercise delay allows time for blood within the lungs to travel to the trachea.