Most causes of dizziness are minor. However dizziness can result from insufficient blood flow and oxygen supply to the brain and spinal cord, such as can be caused by a rapid drop in blood pressure.

Serious disorders that can cause dizziness (note: they usually also cause other symptoms) include heart problems such as a valve disorder or heart attack, stroke, and severe shock.

Dizziness can also be caused by a poorly functioning balance mechanism of the inner ear. The balance mechanism also helps control eye movements, so often the environment seems to be spinning around (vertigo).

Most fainting spells are not dangerous, but if there is any question call for medical help. Sudden loss of consciousness happens more easily when a person is upright. A simple faint is rarely preceded by symptoms such a pain, pressure, constriction in the chest or shortness of breath--just by weakness, giddiness and nausea.

Avoid head positions that cause vertigo. Use caution in occupations where even short episodes of vertigo may be dangerous. Sometimes, gradually increasing the time spent in positions that cause vertigo causes the inner ear to adjust and decreases the positional vertigo.