Postmodern Vertigo is a description of a panic that occurs when somebody considers the reality of their own existence but no longer accepts truth or structure in their thought. Suddenly the thinker no longer believes in anything, everything seeming like a fabrication. Thought become meaningless and a feeling akin to vertigo

Vertigo (medical)

Vertigo is a type of dizziness, where there is a feeling of motion when one is stationary. The symptoms are due to a dysfunction of the vestibular system in the inner ear...

 is experienced. Many writers have described this feeling as "the void" or as a "crisis of postmodernism". Another term which has a similar meaning is anomie. Where as a crisis of postmodernism describes the thought or meaning of viewing existence as a false construct and the void creates a metaphoric representation and Anomie refers to the philosophical dead end, Post-modern vertigo more specifically has been used to refer to this feeling when it takes on a physiological manifestation, causing an increase in heart rate and sweating.

Postmodern vertigo might be a form of existential crisis

Existential crisis

An existential crisis is a stage of development at which an individual questions the very foundations of his or her life: whether his or her life has any meaning, purpose or value...

.