Vertigo is a sensation of spinning dizziness, as though the room or surrounding environment is spinning in circles around the person. Many people use the term to describe a fear of heights, but this is not correct.
Vertigo can happen when a person looks down from a great height, but it usually refers to any temporary or ongoing spells of dizziness that occur due to problems in the inner ear or brain.
It is not an illness but a symptom. Many different conditions can cause vertigo.