DEAR DR. DONOHUE: My wife has nagged me for more than a year to see a doctor because she thought I had Parkinson’s disease. My hand shakes when I do things like bring a cup of coffee to my mouth. Then a fellow worker told me my head was bobbing up and down like I was always agreeing with people. I did see the doctor, and it turns out I have essential tremor and that I should learn to live with it. Isn’t there something to take for it? – D.K.

ANSWER: Essential tremor is also called familial tremor, because it runs in families. A child born to a parent with this tremor has a 50 percent chance of developing it sometime during life. It’s the most common cause of tremor.

The hands shake when they have to perform a purposeful act, like bringing a cup to the lips, writing, eating or doing demanding, fine tasks like sewing. The head is often affected, and that sets it apart from Parkinson’s disease. Even the voice can take on a quavering quality.

One oddity about this tremor is that alcohol can almost always abolish it for a short time. Alcohol isn’t a treatment, but the effect of alcohol on the tremor is another piece of evidence pointing to essential tremor.

The tremor might be nothing more than a nuisance, or it might be so severe that it’s incapacitating.

There are control medicines: propranolol, primidone and gabapentin. If the tremor is intolerable and medicines aren’t effective, surgical procedures like deep brain stimulation usually can quiet it.

Get in touch with the International Essential Tremor Foundation at 888-387-3667 or on the Web at www.essentialtremor.org. You’ll find that the foundation can provide you with a wealth of information.

DEAR DR. DONOHUE: My stepdaughter has a 7-year-old son with physical and mental problems. She was told he has Asperger’s disorder. I can’t find any information on this. Is it hereditary? Is there a cure? Do vitamins and diet influence it? – A.R.

ANSWER: Asperger’s comes from a brain that’s wired a bit differently from most other brains. Whether genes, environment or both bring it about is an unsettled issue. People with the disorder have normal or high intelligence, but they have great difficulties in establishing social relationships. They find it difficult to make eye contact, and they have interests that have little appeal to others. Asperger children tend to be awkward and clumsy, so they avoid athletic participation. Their social isolation reaches a low point in high school, where they are often shunned for being different.

This is not a rare disorder. About one in every 500 has it, although it might not be recognized until later in life.

Intensive training in social skills greatly helps people with Asperger’s to better adapt to society, to better fit in with peers and to have a better life.

I have never seen that diet or vitamins are useful in treatment.

I received a touching letter from an older man who had Asperger’s. He had worked as a mathematician and computer expert for a large corporation, so you see that having Asperger’s disorder doesn’t prevent one from having a successful life. His greatest regret was the lonely life he had led growing up. With the attention this disorder now receives, that aspect of Asperger’s should become a thing of the past.

DEAR DR. DONOHUE: When it becomes hot enough to use the ceiling fan and air conditioner, I get a cough. The cough stops if I don’t use them. Do you think they are the cause? – L.M.

ANSWER: You make a good case for a cause-and-effect relationship, but I can’t tell you why. Perhaps they trigger some idiosyncratic reflex. I don’t know what to tell you to do about this.

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