DEAR DR. DONOHUE: I am engaged to a man who has bipolar illness. I don’t know what this is, and he doesn’t talk about it. Is this something treatable? Will it affect our children? I can’t detect anything wrong with my husband-to-be. What should I be looking for? – R.T.

ANSWER: People with bipolar illness fluctuate between two mood extremes – mania and depression.

When mania strikes, bipolar patients are seemingly tireless. They need little or no sleep. Optimism and energy so infuse them that their judgment can be impaired. Sometimes hallucinations occur.

Depression is the other pole and frequently follows an episode of mania. During depression, the mood turns black and immobilizes patients. In their minds, they are without hope. Energy is gone, and simple tasks take great effort. People have trouble getting to sleep, and frequently waken in the early morning and are unable to fall back to sleep. Anxiety can be great.

Those are the two poles of bipolar illness.

Most likely, this condition has its roots in the disordered production of messenger brain chemicals.

There are many medicines that restore brain chemistry and keep bipolar patients on an even keel and quite productive. Many patients stay on maintenance medicine for life, and lithium is often the drug taken to achieve stable moods.

Many famous people have or have had bipolar illness, and they have made extraordinary contributions to society.

About half the patients with bipolar illness have a family history where other members have or had it. That does not mean that every bipolar patient passes the illness to his or her children. The exact genetics have not been completely unraveled.

DEAR DR. DONOHUE: I am writing in hopes that you can give me some information on skipped heartbeats. I have been bothered by them for some years. The doctor gave me an ECG and said they are premature heartbeats. They make me very anxious. What causes skipped heartbeats? – Anon.

ANSWER: I could paper every story of the Empire State Building with letters asking about skipped heartbeats, so common are they.

Premature beats are extra beats sandwiched between two normal heartbeats. They are of two varieties: atrial or ventricular. Atrial premature beats arise in the upper heart chambers and are as close to being insignificant as anything can come. Ventricular premature beats arise in the lower heart chambers, and people often feel a thud in their chests with a PVC – premature ventricular beat. The early beat causes a heart contraction when it is not completely filled with blood. The next normal beat is delayed a bit, and the heart is overfilled. On that contraction people feel the thud.

Close to 60 percent of normal adults have PVCs. If the heart is otherwise healthy, if the PVCs are not all that frequent and if they don’t trigger a sustained, irregular heart rhythm, then often the best treatment is to ignore them. What causes them? Caffeine, nicotine, carbonated beverages and anxiety might bring on some PVCs, but for most people, a cause is never found.

More serious heartbeat abnormalities, like atrial fibrillation, are discussed in the booklet on that topic. Readers can order a copy by writing: Dr. Donohue – No. 107, 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: Three years ago I had a biopsy of my right breast, and the doctor inserted a stainless steel marker the size of a pinhead in case surgery was necessary. No cancer was found, but the marker is still there. I am concerned about this. Should I be? – S.G.

ANSWER: The stainless steel marker is not going to cause you trouble ever. Forget it.

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.