DEAR DR. DONOHUE: Will you say something about ischemic heart disease? I haven’t seen you write about it. I am interested because that is my diagnosis. My friends have never heard of it either. Is it rare? – P.R.

ANSWER: You’ve seen ischemic (is-KEY-mick) heart disease here many times. It goes by many other names: coronary artery disease, atherosclerotic heart disease, arteriosclerotic heart disease, angina, heart attack, myocardial infarction. It’s anything but rare. It’s the No. 1 health problem in North America.

Ischemia (is-KEY-me-uh) is attached to many conditions. It means a deficient blood supply. Ischemic colitis, for example, is an intestinal disorder due to a poor blood supply to the intestine.

A prominent symptom of ischemic heart disease is angina – chest pain that comes on when a person is moving about. The effort of walking, running, lifting, etc., requires the heart to pump more blood to exercising muscles. That, in turn, calls for increased blood to the heart muscle to sustain the extra effort. Blocked heart arteries don’t allow an additional flow of blood to heart muscle, and it rebels with chest pain.

Exercise is a nonmedicine treatment for ischemic heart disease. Exercise has to be prescribed with as much care as medicine. Often, a stress test – walking on a motorized treadmill while being continuously monitored with an ECG – gives the doctor the information needed to prescribe the safe amount of exercise for a person with ischemic heart disease.

Aspirin to prevent clot formation in narrowed heart arteries, nitroglycerin to open the constricted arteries, statin medicines to lower cholesterol and prevent further narrowing, weight loss, blood pressure control, opening the narrowed arteries with a balloon-tipped catheter and surgically bypassing clogged arteries with grafts are the major treatments for this common ailment.

The coronary artery disease booklet provides a broad view of this condition, including its treatment. Readers can obtain a copy by writing: Dr. Donohue – No. 101, 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 have a bulging disk in my back. My doctor insists it’s because I smoke. I suspect he’s using this to get me to stop smoking. Tell me the truth: Is there any relationship between cigarette smoking and a bulging disk? Don’t they happen for other reasons? – J.G.

ANSWER: Disks are shock absorbers inserted between adjacent backbones. They help the spine withstand the countless stresses it faces in supporting us throughout the day.

Your doctor is telling you the truth. There is a relationship between a bulging (herniated) disk and smoking. Nicotine constricts arteries and reduces blood flow. That impairs disk nutrition. Impaired nutrition weakens the disk and the covering tissues that hold it together. The result is a bulge.

The chronic cough that comes from smoking is another factor in producing a disk bulge. Coughing increases the pressure on a disk and adds to the chance that it will protrude.

There are many other factors involved in disk bulges. Aging is one. So is back misuse, such as bending at the waist to lift instead of bending at the knees.

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.