DEAR DR. DONOHUE: What is the difference between a stroke caused by a bulge in an artery and a stroke caused by an aneurysm? Can a doctor ascertain the cause of such a stroke with a physical examination? Are X-rays or scans necessary? – P.D.

ANSWER: A stroke is the sudden death of brain tissue due to deprivation of blood flow. The more common kind of stroke is ischemic (is-KEY-mick) stroke, a blockage of blood flow to a section of the brain. Ischemic strokes account for 85 percent of all strokes.

The second kind of stroke is a hemorrhagic stroke – a disruption of blood flow to the brain because of a broken, bleeding brain artery. One of the major causes for brain-artery bleeding is the rupture of an artery aneurysm. An aneurysm is a bulge in the artery wall – a weak spot, often there since birth.

Sometimes people with an aneurysm have warning headaches due to small leakages of blood in the weeks prior to a major bursting of the aneurysm. When the aneurysm ruptures, people complain of the worst headache they have ever had, and then they usually lapse into unconsciousness. If they waken, they continue to complain of a terrible headache.

It is difficult to impossible to distinguish by physical exam between a stroke caused by a brain bleed and a stroke caused by an obstruction to blood flow. Scans are needed to make the distinction. Treatment differs radically for the two.

For a broken aneurysm, neurosurgeons place a clip on the broken vessel to prevent any rebleeding (something that often happens). Or a specially trained radiologist can deposit platinum coils into the broken vessel through a tube passed to the brain artery from an artery in the groin. The coils prompt clot formation, which seals the break and prevents rebleeding.

DEAR DR. DONOHUE: I am writing to ask you if you would say something about pecans and almonds. I love them. I eat them by the handful every day before and after breakfast, lunch and supper. I can’t stay away from them. I love them. Is there something in these nuts that is addictive? I keep wanting more of these nuts. I eat them all the time. – K.

ANSWER: I got the message. You love almonds and pecans.

I know of nothing addicting in them other than their taste.

Regular nut eaters are less likely to have a heart attack, but the amount of nuts necessary to achieve that goal is only 1 ounce of nuts, two or three times a week. It’s safe to say you exceed that amount by shovelfuls.

One ounce of almonds is only 22 nuts. An ounce has 169 calories, including 15 grams of fat. The fat is the good kinds of fat – monounsaturated and polyunsaturated.

One ounce of pecans is 20 pecan halves. It has 201 calories with 21 grams of fat, similar to the fats in almonds.

You’re taking in an incredible amount of calories with your nut attraction. I hate to ask, and I do so as delicately as I can, but what is your weight? You’re going to enter the obesity zone if you keep devouring nuts at this rate.

Nuts with a proven track record for heart and artery health include almonds, hazelnuts, peanuts, pecans, pistachios and walnuts. Many authorities claim that all nuts are healthful – in moderation. You’ve gone a bit nuts for them.

DEAR DR. DONOHUE: I was talking to a lady and, after I walked away, I felt lightheaded and broke out in a sweat. Then I found myself on the floor. I passed out for a few minutes. I felt fine and refused to go to the emergency room. I have not had another spell since. Was this a small heart attack? – B.L.

ANSWER: Your description is more like a faint than a heart attack. People don’t usually feel fine after a heart attack, even a small one.

You should tell this to your doctor, but the chance of your having had a heart attack is not great.

DEAR DR. DONOHUE: Is it harmful to try and soften a cough or a sneeze? I have heard that you force germs into your ear when you do. Is that right? – M.P.

ANSWER: It’s possible that, in trying to stifle a cough or sneeze completely, you could generate enough force in your throat to push germs through the eustachian tube into the middle ear. That tube connects the throat with the middle ear and helps control ear pressure.

You can, however, soften a cough or sneeze considerably without running into any danger.

I have a brother who silently positions himself behind people and erupts with a cough or sneeze so loud that people jump a good 10 feet in the air. He claims it’s not done on purpose. Right.

DEAR DR. DONOHUE: I saw that your column has inquiries about leukemias, lymphomas and Hodgkin’s disease.

I would like your readers to know about the Leukemia & Lymphoma Society, headquartered in White Plains, N.Y. It has 66 chapters in the United States and Canada. The society’s mission is to find a cure for leukemia, lymphoma, Hodgkin’s disease and myeloma, and to improve the quality of life for patients and their families. Since its founding in 1949, the society has provided more than $424 million in research.

Your readers can get more information by visiting its Web site, www.LLS.org, or by calling 1-800-955-4572, Monday through Friday, 9 a.m. to 6 p.m., Eastern Standard Time. – A.G.

ANSWER: Thanks. I know readers will be grateful for this source of 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