A sudden onset of dizziness may appear due to motion sickness, an inner ear disturbance or medication, according to Mayo Clinic. Dizziness may also come about due to an infection, injury or an underlying health condition.
Dizziness can be a symptom of an inner ear condition. The inner ear contains sensors that detect back-and-fourth motion and gravity, explains Mayo Clinic. This dizziness, or vertigo, gives the individual a false sense of movement and may occur due to infection, migraines or Meniere's disease, a condition that causes abnormal fluid buildup in the inner ear. Circulation issues may also cause dizziness, and these include sudden drops in blood pressure and poor movement of blood.
Sudden dizziness can also result from neurological conditions, such as multiple sclerosis and Parkinson's disease, states Mayo Clinic. Medications, such as anti-seizure medications, sedatives, antidepressants and tranquilizers may also cause sudden dizziness. Those with anxiety disorders may also find that they experience dizziness, especially if there is a history of panic attacks or agoraphobia (a fear of open spaces).
Anemia, which is low iron in the blood, is an underlying health condition that can cause dizziness, explains Mayo Clinic. Low blood sugar may also cause dizziness, especially in those who have diabetes. People may also experience dizziness from overheating or dehydration due to physical exertion in hot weather or inadequate consumption of liquids.