DEAR DR. DONOHUE: Three weeks ago I rolled over in bed, and immediately the room started whirling. Then I began vomiting. No matter what position I took, I stayed dizzy and nauseated. My doctor diagnosed vertigo over the phone and prescribed Antivert. It didn’t work, so he gave me Valium, and that provided some relief. Since then I have improved, but continue to get dizzy when I lean back or look up. How can I hasten my recovery? – M.F.

ANSWER: There are many causes for vertigo (dizziness), and providing proper treatment depends on identifying the exact cause.

I believe I am on safe ground by saying you have benign paroxysmal positional vertigo – BPPV. You describe it perfectly. It comes on with a change in head or body position. Lying down, rolling over in bed, looking up or bending over can precipitate an attack. The problem lies in the inner ear’s balance organ.

Crystals in the balance organ are disrupted from their normal position and float to places where they trigger a barrage of confusing messages to the brain. The brain responds by making a person feel that his or her surroundings are whirling in space. That, in turn, creates nausea and can make people sick to their stomach. It’s much like what happens during an attack of seasickness.

A doctor in the office, without fancy equipment or expensive tests, can generally make a diagnosis of BPPV. The doctor can provoke an attack by bending the patient’s head 45 degrees to one side and then lowering the patient down on the exam table with the head tilted downward over the end of the table.

If the diagnosis is BPPV, then through a series of head movements, a doctor can reposition the inner-ear crystals back to where they belong. It can take more than one session to achieve the goal, but the maneuvers almost always work.

Not all causes of dizziness are remedied so simply.

The vertigo booklet details its many causes and treatments. Readers can order a copy by writing: Dr. Donohue – No. 801, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.50 U.S./$6.50 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: Peanut butter confuses me. I heard it has good fat. However, the ingredients list hydrogenated vegetable oil. I thought hydrogenated oil is bad for you. – G.H.

ANSWER: Peanut butter delights me. It does have good fat – monounsaturated fat. That’s the kind of fat that protects people from artery hardening, heart attacks and strokes.

Most peanut butters do contain hydrogenated vegetable oil, which keeps peanut oil from separating from peanut butter and floating to the top of the jar. “Hydrogenated oil” is another way of saying “trans fats,” the kind of fat that raises blood cholesterol and leads to artery hardening, heart attacks and strokes. However, the amount of hydrogenated oil is so small that it doesn’t present a danger, and it doesn’t stop me from wolfing down alarming amounts of peanut butter. All-natural peanut butter has no hydrogenated oil at all.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475.