dizziness

The dizziness - A sensation of unsteadiness and lightheadedness. Dizziness may be a mild, brief symptom that occurs by itself, or it may be part of a more severe, prolonged attack of vertigo (a condition typified by a spinning sensation) with nausea, vomiting, sweating, or fainting.

CAUSES
Most attacks are harmless and are due to a fall in the pressure of blood to the brain. This can occur when getting up quickly from a sitting or lying position (called postural hypotension). Similar symptoms may result from a transient ischaemic attack, in which there is a temporary, partial blockage in the arteries that supply the brain.

Other possible causes include tiredness, stress, fever, anaemia, heart block (impairment of electrical activity in the heart muscle), hypoglycaemia (low blood sugar levels), and subdural haemorrhage (bleeding between the outer two membranes that cover the brain).

Dizziness as part of vertigo is usually due to a disorder of the inner ear, the acoustic nerve, or the brainstem. The principal disorders of the inner ear that can cause dizziness and vertigo are labyrinthitis and Ménière’s disease. Disorders of the acoustic nerve, such as acoustic neuroma, are rare causes of dizziness and vertigo. Brainstem disorders that can cause dizziness and vertigo include a type of migraine, brain tumours, and vertebrobasilar insufficiency.

TREATMENT
Brief episodes of mild dizziness usually clear up after taking a few deep breaths or after resting for a short time.

Severe, prolonged, or recurrent dizziness should be investigated by a doctor. Treatment depends on the underlying cause. For example, certain cases of dizziness and vertigo due to a disorder of the inner ear are treated with antiemetic drugs or antihistamine drugs.