One afternoon in the summer, my father, my husband and my two sons set off for the soccer field. As I ran to catch up with them about five minutes later, I could see that my dad was lagging behind. Then, as the others kept walking ahead, he ducked into the tennis courts. The field was only half a block away, but he'd spotted a bench and needed to sit.

My father wasn't out of breath. But at 75, he's had peripheral arterial disease (PAD) for the past several years. It's a common and painful problem that affects older people. Its most frequent symptom is severe pain in the lower legs when a person exercises. Doctors call this "exertional limb pain." When the exertion stops, the pain slowly goes away. That's why my dad had been looking for that bench.

The pain is known to doctors as "intermittent claudication," and is just what it sounds like. Intermittently, the blood flow to the lower limbs slows to a trickle. The leg muscles don't get the oxygen they need. And the lack of oxygen is terribly painful.

Surprisingly, one of the most effective treatments for the condition is exercise. With a routine exercise regimen, the pain isn't as sharp and doesn't last as long. But getting to that point isn't easy. My dad walks -- slowly, until the pain hits. Then he sits until it goes away. Then he gets up and walks some more.

This is typical for a person with PAD. Often they can't walk more than a few blocks before they have to stop and rest. As a result, they complain of feeling old before their time. One woman told doctors, "I walk so slow, nobody wants to walk with me. . . . I mean, I don't want to have to ask anybody to walk that slow."

PAD isn't something that can be cured. The goal of treatment is to lessen the pain and prevent the disease from progressing. In addition to exercise, the other major treatment for PAD is aspirin. And as important as exercise and aspirin is to stop smoking. Without the exercise and the aspirin, or with continued cigarette smoking, the condition can worsen to the point of constant pain in a leg. If circulation to the leg is completely cut off, a person with PAD may be forced to undergo an amputation.

Yet despite how common it is, PAD is a disease that tends not to be diagnosed or treated until a person has been living with it for quite a while. Researchers at university medical centres in Minnesota and Colorado found this in a study of 38 patients with PAD. The patients ranged in age from 44 to 83. When the researchers interviewed them about their experience of the disease, a common theme was how frustrating it was for them before they figured out what their problem was and learned to manage it. Many said they assumed at first that pain with walking was a normal part of the aging process. They simply didn't see it as a medical problem that could be treated.

One man in the study told the researchers, "I never complained [to the doctor] because I didn't think I had a complaint. I thought I had a muscle injury." Others said that even once they realized their pain was an indication of some sort of a medical problem, their doctor couldn't give them an accurate read on what needed to be done.

"I ended up going to several different doctors before I got to one that put his finger on the vascular end of it," one of the patients in the study recalled. "We were talking arthritis, we were talking hip replacement, and went through quite a little stuff for three to four years before I finally got the guy that said, 'You haven't got any circulation.' "

And even after the diagnosis was made, some patients weren't told how they could improve their symptoms. They weren't given the necessary assistance to stop smoking, or weren't put on an exercise program. Yet for most of these individuals, PAD was a major disability. Experts say it ranks up there with chronic lung disease and congestive heart failure in terms of its potential to knock someone off their feet and prevent them from living their lives in the way they'd been accustomed to.

The limitations primarily reflect the problems that people with PAD have in walking, but it also becomes difficult to complete physical tasks.

A September, 2001, study in The Journal of the American Medical Association concluded that PAD was underdiagnosed in primary-care medical practice. If doctors don't know the condition is present, they don't advise treatment. So here's what to look for and ask for.

People who are long-time smokers or have other symptoms of cardiovascular disease such as high blood pressure or high cholesterol are at greater risk for PAD. If you fall into one of those groupings, and you have frequent pain in your legs, ask the doctor to check for PAD.

You may require more effective treatment for high blood pressure or for a lipid disorder. And if you do have PAD, get on an exercise program and aspirin, or some other 'antiplatelet' medication. It's worth treating not only for the immediate relief of symptoms, but also because treatment can prevent other symptoms of cardiovascular disease in the future.

Miriam Shuchman, MD, teaches medical ethics at the State University of New York at Buffalo and the University of Toronto.
mshuchman@globeandmail.ca