January 21, 2013
By Harvey B. Simon, M.D.
Harvard Medical School
Feeling dizzy? If so, you're in good company. Nearly everyone has felt dizzy at some time. It's an unsettling sensation when it occurs unexpectedly, but can also have a certain appeal when it's triggered by a carousel or roller coaster.
Dizziness called vertigo by doctors can indicate a serious illness that needs prompt medical care. But in most people, dizziness is a mild problem that goes away on its own.
To know if your dizziness is worrisome or not, you should understand the types of dizziness and the major causes of this common complaint.
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What is Vertigo?
Some doctors go into a tailspin when their patients complain of dizziness. That's because it means different things to different people. In fact, people use the word to describe several different sensations, including lightheadedness, near fainting and loss of equilibrium. But when doctors diagnose dizziness, they are speaking of vertigo.
Vertigo is also a word with many meanings. The great director Alfred Hitchcock used it as the title for his 1958 film about giddy terror. More often, it's used to mean a fear of heights.
Vertigo is the feeling of motion when none exists. It's usually a turning or spinning sensation, but it's sometimes a tilting or rocking feeling. It can feel like the world is turning around you or like you're twirling in space. Having vertigo is like riding a merry-go-round when you're stationary, like being seasick without the sea.
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The Balancing Act
You don't have to walk on a tightrope to know that good balance is quite an achievement just try standing on one foot while you're brushing your teeth. Balance depends on:
- Your vision
- The nerves in your muscles and joints that tell your brain how your body is oriented in space
- The cerebellum, the part of the brain that functions as your body's gyroscope
But when it comes to vertigo, the system that's most often out of balance is the vestibular apparatus, also known as the labyrinth. It is one part of the inner ear.
The other part is the cochlea, which is responsible for hearing. The two systems are closely related. This explains why inner ear disorders can affect both balance and hearing, causing various combinations of vertigo, hearing loss and ringing in the ears (tinnitus).
Three different vestibular problems account for the three most common types of vertigo:
- Tiny stones in the inner ear's semicircular canals trigger benign paroxysmal positional vertigo (BPPV).
- Excessive fluid is responsible for Meniere's disease.
- Inflammation of the nerve cells causes vestibular neuronitis.
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Benign Paroxysmal Positional Vertigo
The name is a mouthful, but it conveys a lot of information. A mild but annoying condition, BPPV is truly benign. The symptoms are brief and intermittent, or paroxysmal. They are triggered by a change in head position. And the main symptom is vertigo.
BPPV is the most common form of vertigo. It can strike people of all ages, but it's most common in people over 50. In BPPV, dizziness is triggered by head motions, such as:
- Turning over in bed
- Getting in or out of bed
- Bending over or straightening up
- Craning the neck to look up
The vertigo may be severe, but it usually resolves in 15 seconds or less.
Doctors suspect BPPV based on its characteristic symptoms. They can confirm the diagnosis with a simple office test that involves moving the patient's head to certain positions to see if they trigger dizziness.
People with mild cases don't need any treatment. But cases that are prolonged or severe often respond to a series of head movements called Epley repositioning exercises. Doctors believe that BPPV is caused by fragments of debris floating in the inner ear's semicircular canals. The exercises are designed to move the head so the debris floats out of the canals. The treatment, which is effective 75% of the time, is usually directed by a doctor or physical therapist, but some patients can learn to do the exercises themselves.
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Meniere's disease is a common cause of vertigo, especially in older people. The vertigo occurs without warning and often increases over 10-15 minutes before gradually resolving over several hours. Most patients have other symptoms, such as a feeling of ear fullness, a buzzing or roaring sound, and gradual hearing loss. In most cases, just one ear is involved.
Doctors are still not sure of what causes the problem; one possibility is an excess of fluid in the semicircular canals. As a result, doctors may:
- Recommend cutting back on salt intake.
- Prescribe diuretic medications to reduce the volume of fluid. Unfortunately there is no evidence that these interventions are effective.
- Prescribe nausea or motion sickness medications, such as meclizine (Antivert), promethazine (Phenergan) or prochloroperazine (Compazine) to help quiet down severe attacks. They are not generally recommended for long-term use.
A few patients with very severe attacks require surgery, but most patients have much milder problems and many don't require any therapy.
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Vestibular neuronitis can strike at any age. The vertigo lasts for days to weeks, or sometimes even months.
Vestibular neuronitis is an inflammation ("itis" as in tonsillitis or prostatitis) of the vestibular nerve. This major nerve carries information from the semicircular canals of the inner ear to the brain. Because of its location, the condition is sometimes called labrynthitis.
The disorder beings gradually. Vertigo, which is often accompanied by nausea and vomiting, builds to a peak over minutes to hours.
At its worst, vestibular neuronitis is truly disabling. It causes severe imbalance and uncontrollable rapid eye movements that make it difficult to focus or read.
In most cases, fortunately, the symptoms peak within the first day, and then gradually subside over a few days or weeks. Mild problems can last for three months or more, but most people recover completely, even without treatment.
In some cases, vestibular function is permanently impaired, but since the disorder usually affects only one ear, the brain can use information from the normal side to compensate fully.
Since nearly all patients recover from vestibular neuronitis, the main treatment is time. Needless to say, people should stay quiet while they are dizzy. And they should not drive, climb or do other potentially harmful activities. As they recover, patients can resume normal activities.
Doctors often prescribe some of the same drugs used for Meniere's to ease the vertigo and nausea that can be so very uncomfortable. Some physicians prescribe prednisone to reduce inflammation in the nerve, but studies will be needed to see if this approach has merit.
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Other Causes of Vertigo
Certain strokes and transient ischemic attacks ( episodes of stroke-like symptoms) can produce vertigo. Many patients with these true medical emergencies have long-established stroke risk factors, such as high blood pressure, elevated cholesterol levels or atrial fibrillation. In addition, they often have other major symptoms, such as:
- Slurred speech
- Double vision or visual loss
- Clumsiness or tingling of the face, hands or legs
- Incoordination or severe loss of balance
Call 911 and your doctor if you have symptoms of a possible stroke.
Many less urgent problems can also cause vertigo. Some are common but mild, like migraine, medication side effects or panic attacks.
Others are more serious but less common, such as acoustic neuromas and other tumors, multiple sclerosis, certain skull fractures and Parkinson's disease. In most cases, other symptoms and neurologic findings provide enough clues that the problems goes beyond simple vertigo.
If you have BPPV, Meniere's disease or vestibular neuronitis, you should be able to handle the problem with the aid of your primary care physician. But if your problem seems more complex, you may need the help of a "spin doctor," a neurologist or ear, nose and throat (ENT) specialist. You may be in for additional tests, but in most cases they'll set things straight so your world will stop turning.
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Harvey B. Simon, M.D. is an Associate Professor of Medicine at Harvard Medical School and a member of the Health Sciences Technology Faculty at Massachusetts Institute of Technology. He is the founding editor of the Harvard Men's Health Watch newsletter and author of six consumer health books, including The Harvard Medical School Guide to Men's Health (Simon and Schuster, 2002) and The No Sweat Exercise Plan, Lose Weight, Get Healthy and Live Longer (McGraw-Hill, 2006). Dr. Simon practices at the Massachusetts General Hospital; he received the London Prize for Excellence in Teaching from Harvard and MIT.