DEAR DR. DONOHUE: This winter has been hard on me. When I go out and the temperature is less than 35 F, my fingers get very dark, and they hurt. Is this something that happens with age? I am 49. – K.S.

ANSWER: It’s not a matter of age. It’s a matter of oversensitive arteries.

When exposed to cold, everyone’s arteries clamp down. It’s the body’s way of conserving heat. Some people have arteries that take this sort of constriction to extremes. The malady goes by the name of Raynaud’s disease.

People with Raynaud’s have arteries that, when exposed to cold, constrict so forcefully that they effectively cut off blood flow. The fingers (or toes) turn white. As times passes, blood that has been trapped in the fingers from the onset of artery constriction loses oxygen, and the fingers turn blue, the color of blood without oxygen. Finally, when the constriction relaxes, blood rushes into the fingers, and they turn red.

While the color changes take place, the fingers hurt.

When no cause for Raynaud’s can be found, it is called primary Raynaud’s disease. The majority of Raynaud’s patients have the primary illness. In some people, an underlying illness brings on Raynaud’s disease. When that is the case, it is called secondary Raynaud’s. Rheumatoid arthritis and lupus can bring on Raynaud’s. Scleroderma, the illness where the skin hardens, frequently produces Raynaud’s. Secondary Raynaud’s is more common in people over 30.

All with Raynaud’s must not smoke. When they know they are going to plunge their hands into a cold environment, such as reaching into the freezer for food, they should prepare themselves by wearing mittens. Nitroglycerin ointment, applied to the fingers, can sometimes prevent Raynaud’s arterial spasms. So can nifedipine, a drug used to treat angina.

DEAR DR. DONOHUE: Before having surgery for an artificial knee, I had an ECG. It showed “left anterior fascicular block.” That created a fuss, and the surgery was postponed until a cardiologist examined me. After the exam, he said surgery would be OK.

I never learned exactly what that meant or if it requires taking medicine. Please enlighten me. – D.C.

ANSWER: The heart comes equipped with two cables down which the electrical blip generated by the heart’s pacemaker travels to the heart’s lower, pumping chambers. When it arrives there, the heart muscle contracts and pumps blood to the body and the lungs.

The two cables are called the right and left bundles. The left bundle divides into two smaller cables, the anterior and posterior fascicles.

Your left anterior fascicle has a short circuit in it. The electrical signal still reaches the places it should, but it has to take an alternate route.

A left anterior fascicular block, also known as a left anterior hemiblock, is a diagnosis found on many electrocardiograms. When there are no other signs of heart disease, the block does not take on a menacing significance. The heart doctor found no signs of any other heart trouble, so you can forget it. It stays for life, so you will always see it on future ECG reports.

DEAR DR. DONOHUE: I am a 63-year-old male, and I am in good health. This past week, while showering, I felt something hard in my right chest just a little way from the nipple. Is there any chance this could be cancer? Does breast cancer happen to men? – P.J.

ANSWER: Men can develop breast cancer, but not in the numbers that women do. Only a little more than 1,000 North American men can be expected to be diagnosed with it this year. It usually begins as a painless lump located near the nipple. Men can have a mammogram. If it leaves any doubt about the nature of the lump, then the next step would be a biopsy. You definitely need to see your doctor soon.

DEAR DR. DONOHUE: I have noticed that when you discuss diverticulosis, you do not mention something that was emphasized by my doctor. That is not to eat anything that has seeds and not to eat nuts. I don’t find this terribly austere, but I wonder why you don’t say anything about it. Why? – O.R.

ANSWER: The seed-nut question arises when diverticulosis is mentioned. The thought is that a small seed or a small piece of a nut might obstruct the opening of a diverticulum. A diverticulum is a pea-sized bulge of the colon lining protruding through the colon wall. It has a slender stalk, and that’s the site where an obstruction could occur. If the diverticulum’s stalk is obstructed, bacteria multiply in the bulge and cause it to swell. A swollen diverticulum is painful, and now the condition has become diverticulitis.

More and more doctors are eliminating the ban on seeds and nuts because there is no solid proof that they block the entrance to a diverticulum. Having said that, let me add that if your doctor instructs you to avoid seeds and nuts, do so. Your doctor knows much more about your circumstances than I do.