DEAR DR. DONOHUE: I am a 75-year-old male. My doctor discovered that I have an enlarged aorta. He arranged for me to have an ultrasound examination of it. The result is that the enlargement is an aneurysm with a 4.2-centimeter diameter. He said he would have it checked again in six months. Please tell me your thoughts on this. – E.W.

ANSWER: The aorta, the body’s largest artery, arises directly from the heart and travels downward through the chest to the bottom of the abdomen. There it divides into two arteries that supply the legs with blood. All through its course it gives off smaller arteries that provide blood to all parts of the body.

An aortic aneurysm is a weak spot in the wall of that artery. The weak spot permits the wall to balloon outward. The danger from an aneurysm is the possibility of its bursting and causing massive internal bleeding. Most aortic aneurysms form in the abdominal section of the aorta, and most, especially early on, produce no symptoms.

The aorta’s normal diameter is 2.54 cm (1 inch). When the diameter reaches 5.5 cm (2.2 inches), the risk of rupture is great enough to warrant surgical correction. Surgery entails shoring the wall of the aorta with a synthetic graft.

Smaller aneurysms can be safely watched by scheduling periodic ultrasound measurements. Should the aneurysm reach the critical width or should it expand more than one centimeter (0.4 inches) in one year, then it is time for surgery. Some never enlarge.

Doctors are gaining experience with a new technique for aneurysm repair. A stentlike graft is snaked to the site of the aneurysm through an artery in the upper leg. This procedure is less demanding for the patient than is surgery. If it proves to be as effective and long-lasting as surgical correction, it could become the procedure of choice.

DEAR DR. DONOHUE: I have quite a few brown spots on my chest and back. They are rough to the touch and vary in size, with some being as large as a dime. I was told they could be keratoses. Would you explain what that is and if they are malignant? I am 84. I have had them for 10 years. – H.M.

ANSWER: Almost every adult has one or more seborrheic keratoses, and some have hundreds. Their surface can be smooth, or it can be rough with cracks or crisscrossing fissures. The color varies from tan to brown to black, and the size varies from not much bigger than a large freckle to as large as 1.2 inches (3 cm) in diameter. Keratoses have very well-defined borders; they don’t blend into adjacent skin. They look like they’ve been glued on the skin. They might itch.

Seborrheic keratoses are not cancer and do not become cancer. They are a nuisance more than anything. If a person wants, they can be frozen off with liquid nitrogen or scraped off with an instrument called a curette, or they can be left alone.

Your description fits that of seborrheic keratoses. However, brown spots that have not been diagnosed by a doctor’s experienced eye are always a source of concern. You should ask your doctor to take a look at them. Some pigmented skin lesions, as you know, are melanomas. Having had yours for 10 years makes melanoma an unlikely diagnosis, but erring on the side of safety is a sensible policy.

DEAR DR. DONOHUE: My 18-year-old daughter went from never-been-kissed to performing oral sex in a matter of three months. She and her peers do not consider this sex and use no protection. Are there any risks in it? – S.M.

ANSWER: Many venereal diseases can be transmitted through oral sex – male to female or female to male. Gonorrhea, for example, causes a throat infection that is very difficult to treat. Genital warts, herpes and syphilis can all be passed through oral sex. So can AIDS – in very special circumstances.

DEAR DR. DONOHUE: I am a 45-year-old male and was recently ill with diverticulitis. I want to increase my fiber intake, as my physician requests. What is the amount of fiber I should be eating, and what foods would you recommend? Are fiber supplements a good alternative? – D.F.

ANSWER: Diverticulosis is the condition where there are pea-sized protrusions (diverticula) of the colon lining sticking through the colon wall. Diverticulitis is painful inflammation of those diverticula. The protrusions form because the colon has to exert great force to propel undigested, dried-out food through its length. Fiber keeps stool moist, and the colon can evacuate it without generating the great force that causes diverticula to form. Fiber is a preventive treatment for diverticulosis. Resting the colon with liquids is the usual treatment for diverticulitis.

Fiber comes in two varieties: soluble and insoluble. Insoluble fiber means it doesn’t dissolve in water but draws water into the colon, bulks up stool and keeps it soft. Whole-grain wheat and rye, corn, strawberries and raspberries are examples of insoluble fiber. Soluble fiber dissolves in water, and it can lower cholesterol. Whole-grain oats and barley, soy beans, apples and citrus fruits are examples. Most fiber foods are a combination of both kinds.

Before refined flour became the rage in our culture, grains were eaten with their coats intact. The coat of a grain is bran, and it’s the stuff that’s removed during refining. Bran is a wonderful source of fiber. You can buy bran at health-food stores. “Whole grains” are grains with their bran coats.

People should get 25 to 35 grams (0.9 to 1.2 ounces) of fiber a day. A short list of fiber-rich foods includes: .5 cup baked beans, 7 grams of fiber; .5 cup All-Bran cereal, 10 g; 1 apple with skin, 4 g; a banana, 3 g; 10 dried plums (prunes), 6 g; 1 ounce of peanuts, 2.3 g; 3.5 cup air-popped popcorn, 4.2 g. If a person can’t get enough fiber from food, then fiber supplements – Metamucil, Fiberall, Citrucel, FiberCon and psyllium – can provide the daily requirement.

The diverticulosis booklet provides the basic facts on this illness, diverticulitis and their treatments. Readers can obtain a copy by writing: Dr. Donohue – No. 502, 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.

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.