Dizziness - Its Causes and Treatment

Balance Disorders, Lightheadedness, and Vertigo

Apr 20, 2009 Connie Stewart

The experience called dizziness has different meaning for different people. For some, dizziness means a problem with balance, for others, it means a lightheaded ("I'm about to faint") feeling, while, for others, dizziness means the sensation that the room is spinning around. (The specific term for the "room is spinning" sensation is vertigo.)

The Vestibular Disorders Association estimates that dizziness is the second most frequently-stated reason for visits to doctors (only lower back pain ranks ahead of dizziness).

Dizziness is Caused by a Malfunction of One or More of the Balance Entities

The entities that control our sense of location and orientation in space are:

• The eyes
• Receptors, call proprioceptors, located in muscles and skin that send "position" signals to the brain
• A part of the inner ear, called the vestibular apparatus, which informs the brain about the head's position. for example, straight, tilted, or rotating
• The brain, where integration of the signals from the eyes, the proprioceptors, and the vestibular apparatus occurs.

Eyes

New eyeglass prescriptions (including bifocals), cataracts, and glaucoma can cause dizziness because the brain must integrate a new set of spacial/location information from the eyes (and the brain may be receiving conflicting information from the proprioceptors). In most cases of eye/proprioceptor conflict, the brain learns to recompute the relationship between the visual and proprioceptor information, and the sense of dizziness disappears in a few days.

Inner Ear

Inner ear conditions that can create dizziness are:

• viral and bacterial infections
• allergies
• exposure to medications -- certain drugs, called ototoxins, can cause damage to the inner ear. Medications known to be ototoxic include some (but not all) antibiotics, aspirin, and cisplatin (a chemotherapeutic agent)
• degeneration of the inner ear's hair cells due to aging
• a benign tumor of the inner ear, called acoustic neuroma

Brain

• Reduced blood flow to the brain can cause dizziness. Among the most common causes of reduced cerebral blood flow are:

1. orthostatic hypotension--temporary low blood pressure from arising too quickly from a sitting or lying position
2. dehydration
3. arteriosclerosis
4. osteoarthritis--arthritic deposits in the neck can narrow the opening for blood vessels causing diminished blood flow to the brain
5. strokes
6. vasovagal symdrome--a nervous system disorder in which the peripheral blood vessels dilate causing blood to pool in the extremities and deprive the brain

• Non-vascular conditions that can affect balance-coordinating brain centers are:

1. migraine--a strong correlation has been found between migraine headaches and dizziness/balance disorders. Migraine sufferers can experience dizzy spells both during and apart from migraine attacks.
2. brain tumors
3. hyperventilation
4. brain infections or abscesses
5. head trauma
6. endocrine disorders -- diabetes and hyper- or hypothyroidism
7. multiple sclerosis
8. stress, tension, and fatigue

Because some of the conditions that cause dizziness require urgent treatment, every dizziness episode requires investigation by a medical practitioner. Many dizziness/balance disorders can be treated with good results, but treatment depends on identifying the precipitating condition.

More information at the United States National Institutes of Health.