Phylicia Rashad's father died more than 20 years ago of a heart attack, but she has recently wondered if that needed to happen.

"His death certificate read 'cardiac arrest due to hypertension due to diabetes,' " said Rashad, famous for her role as Claire Huxtable on "The Cosby Show." Yet what Rashad never considered is that he may have had peripheral artery disease, a relatively unknown blood vessel condition that affects 8 million Americans, or about one in 40 adults.

Rashad, a longtime advocate for diabetes organizations, has been touring the nation on a media campaign about the disease – shortened to PAD – that causes poor circulation in the legs because of fatty deposit (plaque) buildup in the lower arteries.

"That means there is poor circulation in the arteries leading to the heart and the brain," said Rashad, 60. "It doubles the risk of having a heart attack or stroke, and quadruples the risk of dying from heart disease."

It can also lead to gangrene and require amputation, a fate Rashad's aunt suffered.

In addition to her father, seven of Rashad's family members have died of heart attack or stroke, and each lived with PAD risk factors. In people over 50, those include diabetes, high blood pressure, high cholesterol and smoking tobacco. They also include less-specific potential symptoms such as pain in the legs, thighs, buttocks and cramping when walking or exercising.

"It could be confused with old age, arthritis or increased weight," said Dr. Manuel Mayor, cardiologist at Jackson Memorial Hospital in Miami. "But you need to consider PAD as a possibility."

The condition can be an early warning sign of bigger problems to come, Mayor said, adding that high risk groups are African Americans, Hispanics and the elderly. According to the American Diabetes Association, 10.4 percent of Hispanic adults and 11.8 percent of non-Hispanic black adults have diabetes, nearly twice the rate (6.6 percent) for non-Hispanic whites. In addition, hypertension is more prevalent among African Americans and Hispanics than non-Hispanic whites.

Because PAD – first identified a decade ago – is not something most doctors check for during physical examinations, many people don't know about it. In the September 2007 issue of the medical journal Circulation, three-quarters of Americans polled could not identify PAD. The test, which must be requested, measures the ankle brachial pressure index, or the ratio of the blood pressure in the arms to the ankle.

"If you have PAD, the blood pressure in your leg is lower than in your arm," Mayor said. "Sixty percent of PAD patients … are going to have some disease of the heart."

Treatment for PAD includes exercise and a diet low in saturated fats, trans fats and cholesterol, in addition to blood pressure and cholesterol-lowering medications.

Rashad, who does not have PAD, is campaigning to make it part of regular health screenings. She is working on behalf of the Peripheral Arterial Disease Coalition, which is funded by the Bristol-Myers Squibb/Sanofi Aventis Partnership and medical device maker Cordis Endovascular. The coalition has a Web site, www.padfacts.org.

"Growing up, I remember thinking when people got older they developed diabetes because they got older, or … a heart attack or stroke because they got older, not because there was a buildup of plaque in the arteries, not because there was an obstruction of flow in the blood in the arteries leading to the legs, not because there was PAD," Rashad said. "Make the connection: legs to heart to brain.'