Dizziness is impairment in spatial perception and stability. Because the term dizziness is imprecise, it can refer to vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness.

One can induce dizziness by engaging in disorientating activities such as spinning.Vertigo is a subtype of dizziness in which a patient inappropriately experiences the perception of motion due to dysfunction of the vestibular system. It is often associated with nausea and vomiting as well as a balance disorder, causing difficulties standing or walking. There are three types of vertigo. The first is known as objective and describes when the patient has the sensation that objects in the environment are moving; the second is known as subjective and refers to when the patient feels as if he or she is moving, and the third is known as pseudo vertigo, an intensive sensation of rotation inside the patient's head. While appearing in textbooks, this classification has little to do with the path physiology or treatment of vertigo. Vertigo is the sensation of spinning or having one's surroundings spin about them. Many people find vertigo very disturbing and often report associated nausea and vomiting. It represents about 25% of cases of occurrences of dizziness.

Disequilibrium is the sensation of being off balance, and is most often characterized by frequent falls in a specific direction. This condition is not often associated with nausea or vomiting. Presyncope is lightheadedness, muscular weakness and feeling faint as opposed to a syncope, which is actually fainting.

Non-specific dizziness is often psychiatric in origin. It is a diagnosis of exclusion and can sometimes be brought about by hyperventilation.