The fluid-filled inner ear (labyrinth) consists of two major parts: the organ of hearing (cochlea) and the organ of balance (vestibular system, which consists of the semicircular canals, the saccule, and the utricle). Disorders of the inner ear can affect hearing, balance, or both. Middle ear disorders (see Middle Ear Disorders) cause many of the same symptoms, and a disorder of the middle ear may affect the inner ear and vice versa.

Last full review/revision October 2012 by Lawrence R. Lustig, MD