Vertigo

Vertigo was the irrational fear of heights. According to Bernice Summerfield, few people — even those not suffering from the condition — "would lean on the outside walls, and most kept to the middle of corridors out of instinct." Benny identified a more extreme case as a "full-out phobia". (PROSE: The Glass Prison) Benign positional vertigo was one of its forms, and was an illness of the inner ear. (PROSE: Turn the Light On) Companion Sarah Jane Smith got vertigo when near ledges. (TV: The Five Doctors) Among others, Pydych also suffered from the illness. (PROSE: Drift)

Roz Forrester described her "ears popping" in an isolated case of vertigo. (PROSE: The Death of Art) 20 storeys above ground, the Seventh Doctor overcame his vertigo when he realised that he'd "lost one life that way". (PROSE: The Hollow Men) To recover from a dizzying case of vertigo, Turlough squatted down, shut his eyes and took deep breaths. (PROSE: Deep Blue)

Brigadier Lethbridge-Stewart became "nauseous with vertigo" after first encountering the Waro. (PROSE: The Devil Goblins from Neptune) Fitz Kreiner felt a "real sense" of vertigo when on top of a roof with nothing substantial to hang on to. (PROSE: Escape Velocity)

The Sixth Doctor listed vertigo with agoraphobia and xenophobia as fears which, when mixed together, would form "naked fear". (PROSE: The Ultimate Evil)

Behind the scenes
The DWU's depiction of vertigo is very much at odds with the real world definition. Vertigo is in fact not the fear of heights, but rather the perception of a spinning motion when one is not actually spinning. It is a neurological disorder, not a phobia. is closer to the fear described in DWU material.