DEAR DR. DONOHUE: As grandparents, my husband and I are very concerned about our 10-year-old grandson. We just learned he has Tourette’s syndrome. We have many questions.

Is there treatment? What can this young boy expect to do in life? What’s the cause? – O.L.

ANSWER: Tics are the trademark of Tourette’s syndrome. A tic is a sudden, brief movement or a sudden production of sound.

The movement might be excessive blinking, grimacing, shoulder-shrugging or head-jerking. Or it can be a more elaborate movement, like kicking, jumping or gesturing. The sound might be throat-clearing or the repetition of a word or sound.

Tension builds in a person with Tourette’s syndrome until the tic is expressed. Expression brings relief. Tics occur even during sleep. They can be suppressed for a short time, but inner tension builds until they’re given vent.

The syndrome usually begins between the ages of 2 and 15, most often at age 6 and never after age 21. In about half, tics continue into adulthood, usually at a diminished frequency.

The cause of Tourette’s lies partly in genes and partly in a disturbance of the processing of the brain chemical dopamine. Medicines used for treatment include fluphenazine, pimozide and tetrabenazine.

You grandson can do and be whatever he wants. Tourette’s places few, if any, restrictions on a person’s ability to perform any occupation. Physicians, musicians, athletes – people in all walks of life have achieved great success in spite of having Tourette’s.

Your family should establish a connection with the Tourette Syndrome Association for information and for valuable help. Its phone number is 888-4-TOURET, and the Web site is www.tsa-usa.org. Canadians can contact their association at 800-361-3120 and at the Web site www.tourette.ca.

DEAR DR. DONOHUE: I have cataracts, one larger than the other. The doctor recommended surgery to implant lenses. I have gotten a second opinion stating that

I do have cataracts in both eyes, but that doctor said a new prescription for glasses would improve my vision and that he would not recommend surgery at this time.

My vision is only a little blurry in one eye. I read this in literature given to me by the ophthalmologist: “If symptoms of cataracts are not bothering you very much, surgery may not be needed. Sometimes a simple change in your eyeglasses may be helpful.” That’s where I feel I am right now. Please advise. – B.B.

ANSWER: In most instances, it is the patient who tells the doctor when a cataract needs removal.

When it interferes with everyday activities – reading, driving a car, playing cards, whatever – then the patient is all too happy to have the clouded eye lens removed in order to see clearly once again.

Perhaps the first doctor has a reason why he or she thinks the cataract ought to come out now, one that you and I are not aware of. Ask. If no good reason is forthcoming, then you can safely delay. You might never need the operation.

DEAR DR. DONOHUE: I’m my own boss. I live not far from my office, and I go home for lunch. I take a short nap after eating. It really refreshes me. My wife thinks I might be throwing my body clock out of sync by taking the nap. Am I? I sleep well at night. – G.K.

ANSWER: A nap of less than 30 minutes invigorates many people and increases their afternoon performance. One less than 10 minutes doesn’t do much good.

After a nap, many people experience a light lull in mental functions for about half an hour, but they make no more errors in that time than they would have if they hadn’t taken a nap. From then on, their performance improves. Napping doesn’t throw off your biological clock.

DEAR DR. DONOHUE: I recently read that new research shows that shrimp does not contain high cholesterol levels. The article said that shrimp contains noncholesterol sterols. Is there any validity to this? If so, does this mean that eating shrimp that hasn’t been deep-fried or prepared with butter is fine for a heart-healthy diet? – R.B.

ANSWER: If there is new research that says shrimp has no cholesterol, I am unaware of it.

In sources I use for food constituents, 3 ounces of shrimp has 166 milligrams of cholesterol. However, a few cholesterol facts come to the rescue for shrimp lovers.

We are responsible for most of the cholesterol in our blood and in our body. Our liver makes it. Fats spur the liver’s production of cholesterol. Shrimp has very little fat, so it doesn’t stimulate cholesterol production.

Furthermore, shrimp has omega-3 fatty acids. These substances do many healthy things, one of which is lowering blood cholesterol. Shrimp wins on this point. Shrimp can be eaten in a heart-healthy diet. Will you let me know where you read the new information?

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. Readers may also order health newsletters from www .rbmamall.com.