In 2003, a blood pressure reading of 129/84 was considered normal. Today, 129/84 will get you a prehypertension diagnosis and a warning from your doctor. To be considered normal now, your blood pressure would have to be lower than 120/80. Cholesterol standards are changing, too, with doctors demanding higher levels of HDL, the good cholesterol, and lower levels of LDL, the bad cholesterol.

“One year, you can be told your cholesterol and blood pressure are perfect, and the next year, with the same cholesterol and blood pressure, you may be told ‘wait a minute, we have to do something about this,’ ” says Dr. Jonathan Fialkow, a cardiologist at the Baptist Cardiac & Vascular Institute in Miami.

The changing standards stem from ongoing clinical trials, says Dr. Frank Astor of Blue Cross/Blue Shield of Florida. Astor acknowledges that many patients think the pharmaceutical industry is behind the changes — since doctors often prescribe drugs to help control blood pressure and cholesterol, but he doesn’t believe it. “I know it’s wonderful to look at conspiracies, but it’s about science and it’s about accurate parameters,” he says. “There’s so much data out there that it would be impossible to hide. It would be glaring to so many people if indeed there were false readings put out there because of one industry’s interests. It wouldn’t float.”

Rather, Aster expects ongoing studies, including the Framingham Heart Study, which began in 1948, to result in even lower guidelines for blood pressure, bad cholesterol, weight and other criteria. “We understand that the science of medicine changes significantly every five years,” he says. “Patients have a responsibility to keep themselves educated.”