According to MedicineNet.com:
Vertigo is a feeling that you are dizzily turning around or that things are dizzily turning about you. Vertigo is usually due to a problem with the inner ear. Vertigo can also be caused by vision problems.
The word “vertigo” comes from the Latin “vertere”, to turn + the suffix “-igo”, a condition = a condition of turning about). Vertigo is medically distinct from dizziness, lightheadedness, and unsteadiness.
After a chase on the rooftops of San Francisco, John ‘Scottie’ Ferguson (James Stuart) starts suffering from it. He’s even afraid to get on small ladders. He has to quite his job and leaves the police force to become a private detective. He’s asked by an old friend to shadow his wife as she has been acting very strange lately. He takes the job and follows the woman everywhere she goes around San Francisco, which results in not only some beautiful shots of the city, but also a suspenseful thriller as only Hitchcock could make them.
Of course the movie wouldn’t be called Vertigo if nothing was done with this fact. Without telling more about the story, Irmin Roberts, one of Hitchcocks cameramen, invented the “Vertigo zoom”. This zoom effect should show the effect high places had on John when he looked down. The effect convinces. The way the shot is made is by moving the camera forwards (or backwards) while using a zoom lens in such a way that the subject you are shooting (a set or a person) stays the same size. This causes a change in perspective and results in a very surrealistic effect. After Vertigo it has become one of the tricks of the movie making trade, which has been used many times since Vertigo.
Here are some examples out of Vertigo, Goodfellas, Jaws, Poltergeist and The Fellowship of the Ring to show the effect:
James Stewart (Hitchcock worked with him on several movies) impresses and show the fear John has, he also show how good the private detective is at his job. When the movie came out it the reviews were mainly bas ones as the movie was so different from the way stories were shown previously. Years after the movie came out people started appreciating this movie and saw its qualities. It just shows that Hitchcock was far ahead of his time by experimenting with different ways to tell a story.
Just like Psycho, Vertigo is another perfect movie made by Hitchcock. The suspense you’d expect is present and again he tells his story in an unexpected way, just like he did in Psycho. Although Psycho is still my favorite Hitchcock movie, Vertigo takes second place.