DEAR DR. DONOHUE: My cardiologist says I am the healthiest 86-year-old man he has ever seen. He gave me a carotid-artery ultrasound exam and says I have a 40 percent blockage in one of them. What is the consequence of such a blockage? Does it kill you? Does it do something bad to the brain? I didn’t get this old by reacting to everything told to me by doctors or by lawyers, either. – G.O.

ANSWER: There are two carotid arteries, one on the right and one on the left side of the neck. They are the main suppliers of blood to the brain. An obstruction in one or both carotid arteries can bring on a stroke and sometimes death.

One way of avoiding a stroke from a blocked carotid artery is to remove the obstruction surgically in a procedure called an endarterectomy. The surgeon opens the artery and scoops out the obstruction. The obstruction is plaque, a mishmash of cholesterol, fat, clotting proteins and blood platelets.

The question of who needs surgery generates great debates. Most agree that if there is a 70 percent narrowing of the artery and if the person has symptoms, then an operation is advisable. Symptoms include such things as temporary weakness of a leg or arm, a hesitancy in speech or a transient impairment in vision. If a person with symptoms has even a 50 percent to 70 percent obstruction, many believe that constitutes grounds for operation.

If a person has an obstruction but no symptoms, then matters are a bit cloudier. One large school holds that an obstruction of 60 percent or more in an asymptomatic person with a life expectancy of five or more years should be removed if the person is in good health.

You have a blockage of only 40 percent. Aside from all the good things that got you to 86 without kowtowing to doctors or lawyers, you don’t need to do anything else for the present.

There are other techniques for removing carotid blockages. Angioplasty is undergoing trials right now.

DEAR DR. DONOHUE: I am a 78-year-old woman. I had open-heart surgery almost two years ago. I feel good and am very active. I went for a checkup and was told I had a urinary infection. I have no signs of infection. How is it possible to have an infection without feeling anything wrong? – A.M.

ANSWER: Urine should have no bacteria in it. It’s supposed to be sterile. You don’t have a true infection. You have what’s called asymptomatic (no symptoms) bacteriuria (bacteria in the urine). Around 20 percent of women older than 65 and 10 percent of men of that age have it.

The rate of spontaneous cure of asymptomatic bacteriuria is quite high. For that reason, treatment is often not suggested unless the person has evidence that urine flow is somewhat obstructed.

Asymptomatic bacteriuria at other ages, however, is treated. Children, for example, are usually put on antibiotics to eliminate the germs from the urine.

DEAR DR. DONOHUE: What NSAID can be taken along with aspirin that has been prescribed for its anti-clotting properties to prevent heart attack? – H.P.

ANSWER: “NSAID” is the acronym for nonsteroidal anti-inflammatory drug, the large class of drugs whose greatest use is for arthritic joints.

Ibuprofen, whose brand names include Advil and Motrin, can decrease aspirin’s effectiveness in preventing blood platelets from sticking to each other and forming clots in arteries. Clots in heart arteries cause a heart attack.

Whether other anti-inflammatory drugs – there are more than 18 – have the same effect has not been established.

Voltaren, whose generic name is diclofenac, does not appear to interfere with aspirin’s ability to stop platelets from sticking to each other.

DEAR DR. DONOHUE: I was wakened from a deep sleep by pain in my big toe that was so bad, I thought it would kill me. It turned out to be gout. I took Indocin for it. Is there something better? Why does it happen in the big toe? The doctor says that if I have another attack, I have to go on lifelong medicines. Is that standard practice? – G.D.

ANSWER: Gout comes from the infiltration of uric acid crystals into joints. Uric acid comes from the daily turnover of body cells. Nucleic acid within cells gives rise to it. An elevation of the blood uric acid level occurs when the body makes too much or when the kidneys filter too little. In men this mostly happens after age 40; in women, after menopause.

The pain of gout is extreme. The affected joint turns beet red and swells. If it’s the big-toe joint, as it often is, the weight of a sheet on it is unbearable. The big-toe joint is not the only joint that can fall victim to gout. The top of the foot and the knee are other common places for an attack. Joint temperature makes the big toe the most vulnerable joint. Uric acid forms crystals at cooler body temperatures, and the big-toe joint is the coolest joint in the body.

Indocin, one of the common anti-inflammatory drugs, is often the drug of choice for an acute gout attack. If it doesn’t work quickly, there are other anti-inflammatory drugs that can be used. Naproxen is an example. The time-honored gout medicine colchicine is an effective drug. Steroids such as ACTH and prednisone are other reliable treatments for an acute attack. If Indocin works, there’s no reason to switch.

When a person has three or more attacks in a year, standard practice calls for preventive treatment. Zyloprim (allopurinol) stops uric acid production, and probenecid increases uric acid excretion into the urine. They both lower blood uric acid levels and prevent further attacks.

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.