DEAR DR. DONOHUE: I would like you to tell me what causes the blockage of heart arteries. Is it mental stress, like the kind that comes from verbal fighting? Please explain the reasons why these arteries become blocked. – L.S.

ANSWER: Artery clogging is atherosclerosis (“athero” being “fat-like” and “sclerosis,” “hardening”). It happens not just to heart arteries but to arteries throughout the body. When it happens to brain arteries, strokes result. When it happens to leg arteries, pain on walking – peripheral vascular disease – is the consequence. It develops early in life, and it starts with white blood cells, cholesterol and fat infiltrating the artery wall. In time, a mound builds on the wall. If the top of the mound breaks off, as it frequently does, blood platelets (clot-forming cells) settle on the broken mound and can completely occlude the flow of blood through the artery. In the heart, the result is a heart attack.

Many things set this process in motion. A high-fat, high-cholesterol diet is one. Untreated high blood pressure is another. Aging, cigarettes and obesity contribute to it. Men who have a waist measurement greater than 40 inches (102 cm) and women with one greater than 35 inches (88 cm) are prone to atherosclerosis. Physical inactivity is another factor.

Yet there are physically active, lean, health-conscious people who fall victim to atherosclerosis and have heart attacks and strokes. Why? Genes. Something in their inherited DNA predestines them to artery clogging.

New information indicates that artery-wall inflammation is another important ingredient leading to artery occlusion.

Most experts believe mental stress can be a significant factor in the process. Stress triggers the release of chemicals like adrenaline, and chronically high blood adrenaline levels can damage artery walls. This is the reason why many heart doctors have their patients practice calming techniques like meditation.

The heart attack booklet discusses this problem in greater detail. To order a copy, write to: Dr. Donohue – No. 102, 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: I was on Vioxx for many years. When I found out it could cause trouble, I stopped taking it. I would like to know if I could have any side effects later, long after not taking it. I have had lawyers calling me, but I am not interested in any lawsuits. I am interested in knowing if trouble is in store for me. Is it? I can’t get my doctor’s office to give me any information. They are afraid of lawsuits. – V.V.

ANSWER: Vioxx, a very popular arthritis medicine, was taken off the market in September of 2004 because a large trial of patients using it showed that it increased the risk for heart attack and stroke. Those attacks occurred while people were taking the medicine. The tentative explanation is that the drug can stop arteries from dilating, something necessary to keep blood supplying the heart and brain. It might also interfere with natural body substances that keep blood platelets from sticking to each other. When that happens, clots form within arteries, and that blocks blood flow to the heart and brain. These things happen when a person is taking the drug.

No one has made any statements that Vioxx users could be subject to problems once they discontinue the drug. A reasonable deduction is that they would not.

If any statements to the contrary are made, I’ll let you know.

DEAR DR. DONOHUE: A few years ago I was diagnosed as having a gallstone. A recent ultrasound shows that my gallbladder is full of stones. I have no pain nor any symptoms. Should I have surgery now? – B.B.

ANSWER: Many people have gallstones, but only a few of them have symptoms. Symptoms include pain, usually in the upper right side of the abdomen and usually coming on after eating a fatty meal. Attacks also include nausea and vomiting.

If gallstones are quietly sitting in the gallbladder, not kicking up a fuss, surgery is not necessary.

DEAR DR. DONOHUE: My wife and I, both in our late 70s, enjoy a glass of wine with dinner. On weekends, we sometimes have a cocktail before dinner or later in the evening. Is this too much alcohol for people of our age? – B.P.

ANSWER: Most men, even at your age, can safely have two alcoholic drinks a day. A drink is 12 ounces of beer, 5 ounces of wine or 1.5 ounces of 80-proof alcohol. A woman should limit herself to one drink a day.

Your wife can indulge in the extra cocktail on weekends without fear.

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.