What is the difference between Meniere's disease and benign paroxysmal positional vertigo? A few days ago, I had severe vertigo that lasted almost 24 hours. I did not have tinnitus or hearing loss, and I felt no pressure, just a very hard vertigo. It started when I tried to wake up. I couldn't even stay sitting down. Somebody told me it was Meniere's, but my symptoms seem like BPPV. How can I know? I'm 37.

Z.

Correct diagnosis of dizziness requires careful attention to historical detail. First and foremost, the doctor and the patient must be certain they are talking about the same thing.

Vertigo has a fairly specific meaning. Vertigo implies a sense of motion: Usually the patient's visual field (what you see when you keep your eyes open) moves in some way. There is, of course, the classic whirling sensation -- the type of vertigo you had as a child, when you would spin around and around. What if the visual field jerks, tips, moves from side to side or moves up and down? These are also examples of vertigo. There must always be the sense of movement: Either I am moving or the room is moving.

Vertigo is not a lightheaded sensation, a feeling that one is about to pass out, unsteadiness or an inability to stand upright (or walk) without falling. Vertigo may cause these other problems, but such symptoms are more appropriately labeled dizziness or disequilibrium.

After clarifying the patient's symptom, the next step is to understand the very first episode. In your case, since your vertigo has not been episodic, the doctor should dwell on the details of that 24-hour period in which you were symptomatic. Was it true vertigo? How disabled were you by this episode? Were you bedridden the whole day? Were you vertiginous even while lying motionless in bed? Were you nauseated, and did you vomit? Did you have any auditory symptoms? (You stated that you did not, but I want to emphasize that a doctor should ask about tinnitus, hearing loss, aural pressure -- a sense that you need to pop your ears -- and ear pain.)

Next, the doctor should ask about time: How long did the vertigo last? Did it last only a few seconds at a time (but keep recurring all day) or did it last the whole day, nonstop? Next, provocative factors: Was the vertigo provoked by specific positional changes, or did it happen even when you were motionless? If there were specific positional changes, what were they?

The general medical history is very important. Have you ever had ear infections, ear trauma or ear surgery? Have you had recent head trauma? What other medical problems do you have? What medications do you take -- and have any of these been changed recently?

The physical examination, too, is very important, though most ear, nose and throat doctors agree that the most important data come from the history.

The only way that I could be certain of your diagnosis would be to have this discussion with you and then examine you. I can, however, give you a few bits of information to clarify your diagnostic dilemma.

Benign paroxysmal positional vertigo (BPPV) is uncommon in younger individuals like yourself. The patient experiences true vertigo briefly (lasting only a few seconds) and is provoked by changes in head position. The vertigo can be fatigued: In other words, if you repeat the provocative head movement over and over again, the vertigo will be less and less intense with each repetition. The problem may last for weeks, sometimes longer, and then vanish mysteriously, only to recur months or years later. Meniere's disease, on the other hand, classically involves four symptoms: vertigo, hearing loss, roaring tinnitus and aural pressure. The vertigo of Meniere's disease lasts several hours, rarely more than one day, and is constant and disabling.

Or you may have had an entirely different problem: vestibular neuritis. Vestibular neuritis is characterized by the sudden onset of vertigo that lasts for one to a few days. The vertigo is disabling and is usually associated with nausea and vomiting. There are no auditory symptoms, and there are no other unusual neurological symptoms (e.g., headache, seizures, double vision, muscle weakness). Vestibular neuritis often follows a cold or flu and is commonly thought to be due to a viral inflammation of the balance nerve (vestibular nerve). There are, of course, many other possible diagnoses. Your best bet would be to discuss this problem with an ear, nose and throat specialist.