For film noir fans, the word vertigo conjures images from the 1958 Alfred Hitchcock film of the same name. The movie stars James Stewart as a private investigator who attempts to follow Kim Novak despite suffering from trauma-induced acrophobia (a fear of heights) and vertigo (a false sense of rotational movement). To emphasize the condition for which Stewart’s character suffers, Hitchcock used clever camera movements and music that create a visual sense of a spiraling free-fall for the viewer.

For the approximately 40 percent of Americans who will experience vertigo in their lives, Hitchcock’s depiction of the condition is all too real, acting as a reminder of the discomfort of this temporary condition. What causes vertigo, and how can you tell if you have it? Our health experts separate the facts from fiction.