Ménière's disease turn, is strongly associated with developing MD, but not everyone with EH develops MD: "The relationship between endolymphatic hydrops and Meniere's disease is not a simple, ideal correlation." Additionally, in fully developed MD the balance system (vestibular system) and the hearing system (cochlea) of the inner ear are affected, but there are cases where EH affects only one of the two systems strong enough to cause symptoms. The corresponding subtypes of MD are called "vestibular MD", showing symptoms of vertigo, and "cochlear MD", showing symptoms of hearing loss and tinnitus. The mechanism of MD is not fully explained by EH,
The Word for World Is Forest Athsheans: one of the elders of the Athsheans says to Selver "You've done what you had to do, and it was not right." "The Word for World is Forest" also challenges the idea of colonialism; the Terran colonists are depicted as being blind to the culture of the Athsheans, and convinced that they represent a higher form of civilization. Le Guin also challenges the metaphorical preference in Western cultures for pure light, in contrast to deeper and more complex shadows. Throughout the novel Le Guin draws a contrast between the Athshean way of integrating with the ecology of the planet,