Dizziness is one of the most common complaints encountered in the general population. Although patients often use the same word to describe it, they are actually describing very different experiences. Some patients say the room is spinning, some feel lightheaded, some feel unsteady, and some describe a sensation as if the ground were slipping out from under their feet. This distinction matters greatly for diagnosis.
True vertigo is the sensation that oneself or one's surroundings are spinning. This sensation arises from a mismatch originating in the balance organs of the inner ear or in the balance centers of the brainstem or cerebellum. The sense of balance is formed by combining signals from the inner ear, the eyes, and the joints in the brain. When there is inconsistency among these signals, the brain interprets this discrepancy as a spinning sensation.
Vertigo is divided into two main groups according to where it originates. The first is peripheral vertigo, arising from the inner ear, and the second is central vertigo, arising from the brainstem or cerebellum. This distinction is clinically important, because central vertigo can point to more serious underlying causes.
The most common cause of peripheral vertigo is benign paroxysmal positional vertigo. In this condition, calcium crystals in the inner ear become dislodged and fall into the balance canals. When the head is moved into a certain position, for example when getting out of bed or turning the head, a brief but intense spinning sensation occurs. These episodes usually last from a few seconds to about a minute. Diagnosis is made with a simple examination in which the head is turned in specific directions. Medication is generally not needed for treatment. Maneuvers that reposition the crystals produce marked improvement in most patients after a single session.
Vestibular neuritis is another peripheral cause, resulting from sudden inflammation of the inner ear nerve. In this condition, dizziness begins suddenly and can last for hours or even days. Nausea, vomiting, and unsteadiness accompany it. It usually follows a viral infection. Medications that relieve symptoms are used in treatment, but staying active and doing balance exercises during recovery speeds up the healing process.
Meniere's disease is a condition caused by increased fluid pressure in the inner ear. In this disease, dizziness occurs in episodes accompanied by ringing in the ears and hearing loss. Episodes can last from minutes to hours. Salt restriction and certain medications can reduce the frequency of episodes.
Central vertigo is less common but requires more careful evaluation. A stroke in the brainstem or cerebellum can, in some cases, present with dizziness alone. Certain findings help distinguish this picture from peripheral vertigo. Dizziness that begins suddenly, is accompanied by a severe headache, or comes together with double vision, slurred speech, facial numbness, or gait disturbance should raise suspicion of a central cause. In such cases, the patient should be evaluated urgently.
In a patient presenting with dizziness, evaluation focuses first on how the complaint is described. Questions address when it began, how long it lasts, its relationship to head movements, whether it is accompanied by hearing loss or ringing in the ears, and whether any neurological symptoms are present. On examination, eye movements, balance tests, and head positioning tests provide important clues. Imaging is needed when a central cause is suspected or to rule out central causes.
Dizziness usually does not indicate a serious illness and often stems from treatable causes. However, dizziness that begins suddenly, is severe, and is accompanied by neurological symptoms always requires urgent evaluation.
