A feeling that objects in the environment are spinning around or moving, or the sensation that the head is whirling, or sometimes the feeling that the floor and walls seem to sink and rise, or that the body is leaning. Often the feelings are accompanied by nausea, vomiting, and difficulty walking, and can be relieved by sitting or lying still. Usually vertigo indicates disease of the vestibular end-organ, the vestibular division of the VIIIth nerve, vestibular brainstem nuclei, or vestibular parts of the cerebellum. See dizziness.