Acrophobia

Acrophobia is an extreme or irrational fear or phobia of heights, especially when one is not particularly high up. It belongs to a category of specific phobias, called space and motion discomfort, that share similar causes and options for treatment. Most people experience a degree of natural fear when exposed to heights, known as the fear of falling. On the other hand, those who have little fear of such exposure are said to have a head for heights. A head for heights is advantageous for hiking or climbing in mountainous terrain and also in certain jobs such as steeplejacks or wind turbine mechanics. People with acrophobia can experience a panic attack in high places and become too agitated to get themselves down safely. Approximately 2–5% of the general population has acrophobia, with twice as many women affected as men. The term is from the ἄκρον, ákron, meaning "peak, summit, edge" and φόβος, phóbos, "fear". "Vertigo" is often used to describe a fear of heights, but it is more accurately a spinning sensation that occurs when one is not actually spinning. It can be triggered by looking down from a high place, by looking straight up at a high place or tall object, or even by watching something (i.e. a car or a bird) go past at high speed, but this alone does not describe vertigo. True vertigo can be triggered by almost any type of movement (e.g. standing up, sitting down, walking) or change in visual perspective (e.g. squatting down, walking up or down stairs, looking out of the window of a moving car or train). Vertigo is called height vertigo when the sensation of vertigo is triggered by heights. Height vertigo is caused by a conflict between vision, vestibular and somatosensory senses. This occurs when vestibular and somatosensory systems sense a body movement that is not detected by the eyes. More research indicates that this conflict leads to both motion sickness and anxiety. Confusion may arise in differentiating between height vertigo and acrophobia due to the conditions' overlapping symptom pools, including body swaying and dizziness.