• Mayo Clinic Q and A: Number of disorders can trigger vertigo

medical illustration of inner ear describing vertigoDEAR MAYO CLINIC: What causes vertigo? Does having it one time mean I’m more likely to experience it again?

ANSWER: Vertigo is a sensation that either you or your surroundings, or both, are spinning or moving when they are not. Some people confuse vertigo with dizziness, but there is a difference. Dizziness typically is a feeling of being lightheaded, or it may be a loss of balance that makes you unsteady on your feet. Dizziness usually does not involve the feeling that either you or something in your environment is moving.

A number of disorders can trigger vertigo. The most common is a condition called benign paroxysmal positional vertigo, or BPPV. If you have BPPV once, you are at an increased risk of getting it again. In many cases, BPPV can be successfully treated.

For many adults, BPPV is the underlying source of vertigo. With BPPV, vertigo happens when you move a certain way. Sitting up, tilting your head or lying down may all trigger vertigo if you have BPPV.

BPPV is a result of tiny crystals in your inner ear being out of place. The crystals make you sensitive to gravity and help you to keep your balance. Normally, a jelly-like membrane in your ear keeps the crystals where they belong. If the ear is damaged — often by a blow to the head — the crystals can shift to another part of the ear. When they are out of place, the crystals make you sensitive to movement and position changes that normally don’t affect you, sparking vertigo. Occasionally, especially in older adults, the specific cause of BPPV cannot be determined.

To diagnose BPPV, doctors use a technique called the Dix-Hallpike test. During this test, you are placed in the position that usually causes your vertigo to begin. When the symptoms start, your doctor checks to see if they are accompanied by a certain type of involuntary eye movement response. If so, that usually confirms BPPV. If the test does not yield clear results but you have a history of vertigo and your symptoms are intermittent, other tests may be used to detect involuntary eye movements or to test your ability to maintain your balance. Physical therapy and other diagnostic tests also may be necessary.

Treatment of BPPV involves your doctor guiding you slowly through a series of specific head movements that reposition the crystals in your inner ear where they no longer cause vertigo. For the majority of people with BPPV, vertigo goes away after just one repositioning treatment. For about 50 percent of people successfully treated for BPPV, however, the vertigo does come back within a year.

Your doctor will likely teach you how to perform the repositioning procedure by yourself so you can do it at home. If the problem is not resolved after trying the repositioning treatment for a couple of days, follow-up treatments with your doctor may be necessary.

Beyond BPPV, examples of other medical conditions that can cause vertigo include vestibular neuritis and labyrinthitis. Both involve inner ear damage that is usually the result of an infection. Meniere’s disease, a rare inner ear disorder, also can lead to vertigo. The underlying cause of Meniere’s disease is not clearly understood. These disorders can be harder to treat than BPPV. In many cases, though, the vertigo they cause can be effectively managed so it doesn’t interfere with a person’s daily activities.

Experiencing vertigo can be very unnerving, especially if you’ve never had it before. Although it is not a medical emergency, if you have an episode of vertigo, see your doctor as soon as possible to have your condition evaluated. It is important to find the underlying cause of vertigo so it can be effectively treated. — Neil Shepard, Ph.D., Audiology, Mayo Clinic, Rochester, Minn.