The examples of sudden deafness and Meniere's Disease are used to discuss the possibilities of causal therapy for inner ear dysfunctions. In sudden deafness, etiological and therapeutic considerations are focused on the problem of disorders of the arterial and venous microcirculation, contributing to oxygen deprivation of the organ of Corti. Disruption of the arterial microcirculation leads to irreversible damage of the sensory organ within minutes and non-responsiveness to therapy, whereas even serious venous circulation disturbances can be treated successfully within days after onset of the acute disease. While knowledge of pathological changes in sudden deafness is still limited, temporal bone studies in Meniere's disease provides important information on its pathogenesis. Many authors have described enlargement of the cochlear duct as evidence for endolymphatic hydrops. Maximum enlargement of the endolymphatic system disrupts the membrane system which separates endo- from perolymph, and can be confirmed by histologic examination. This indicates that a change of the ionic concentration in the inner ear fluids is responsible for inner ear dysfunction. Thus, the acute Meniere attack can be explained as a consequence of the "burst hydrops." Because of the still unknown etiology of hydrops, only its consequences can be treated at the present time: i.c., immediate removal of the toxic potassium concentration from the perilymph by increasing the microcirculation of the inner ear before irreversible damage occurs.