The idea behind medical screenings is practical and useful: Test patients to see if they exhibit specific symptoms of specific diseases or conditions. If the symptoms are found, the person has the disease. It's that simple, at least from a patient's point of view.

But from a doctor's point of view, it's not always that simple. Healthcare should be personalized.

"There's no screening recommendation that should be applied to everyone," said Dr. Samuel Rao, family physician at Williamsport Family Practice. "It really does need to be more tailored to the individual. I think that was part of the problem with the recent recommendations."

The "recent recommendations" Rao referred to are the revised breast-cancer screening guidelines released in November by the U.S. Preventive Services Task Force. The USPSTF, an advisory panel of preventive-care physicians, recommended against routine mammograms for women aged 40 to 49 who show no risk factors for breast cancer.

This was a change from a previous recommendation, released in 2002, that all women aged 40 or older get mammograms every year or two. The new recommendation sparked protests from many individuals and organizations, including cancer patient advocates and cancer specialists. Other organizations, such as the American College of Physicians, supported the USPSTF's guidelines.

Again, something that should be clear and simple instead is confusing and complicated.

So how should ordinary folks view the new breast-cancer screening guidelines? And what is the purpose of screening at all?

Why get screened?

Cathy Ware is the vascular care specialist with Washington County Hospital. She screens patients for peripheral arterial disease, a condition in which fat, fibrous tissue or other material in the blood builds up to partially block an artery. PAD can lead to pain, numbness, reduced ability to fight infection, even stroke.

Ware said the highly accurate screening involves checking blood pressure on the arms and legs and two ultrasound scans. She said the hospital offers free PAD screening for area residents aged 50 or older. People younger than 50 might also qualify for a free screening if they have certain risk factors such as diabetes.

And that, in a nutshell, is the key to medical screenings: They are typically intended for people who show risk factors - family history, lifestyle behaviors or physical symptoms - of a certain condition.

Ware said she asks patients about their lifestyle, medical history and behaviors.

"When they complete their paperwork, we ask about their particular risk factors," she said. "Do they have high blood pressure or high cholesterol? Do they smoke? Are they diabetic? Do they eat a lot of fried foods? We try to make it very individualized."

The best approach: Get personal

Rao agreed that an individual approach works best when trying to evaluate a person's health. And talking is the most important part of that.

"That's really what's most important: the conversation between doctor and patient. That and family history," he said. "You can't diagnose things just from a test. You have to rely more on what the patient is telling you."

Rao said certain conditions are red flags for doctors. These include high blood pressure; obesity or being overweight; smoking; and high cholesterol. When physicians see these behaviors and symptoms, they'll look for harmful impacts on health. Part of that might involve diagnostic screenings.

Rao said he learned in medical school that 70 percent of a diagnosis comes from talking with a patient or from his or her family history. Another 20 percent comes from conducting a physical examination.

"Maybe 10 percent comes from testing," he said. "Talking is the most important part. Sometimes I see people getting away from that."

Misleading screening results

One problem with screenings is the presumption that the results will be clear and unequivocal. Often this is the case, but not always. Rao compared an organic, living human body to an inert machine.

"We're not a car," he said. "Screening results can be false positives, false negatives."

Some screening results are less clear than others, Ware agreed.

"The (ultrasound) test for the aneurysm is pretty black and white," she said. "But if you take a mammogram and you see a mass, you may not know what that mass is until you do some further test."

Problems highlighted by the USPSTF in its November recommendations on breast-cancer screenings included false results. A false-positive result can lead to unnecessary worry, unnecessary additional tests, even unnecessary surgery.

Then there are false-negative results, in which a disease is missed by a test.

"A person thinks, 'Oh well, negative means I don't have to do anything else,'" she said. "That's not necessarily true. For instance, your screening test may not show carotid disease now, but you're eating a diet high in fatty foods and have untreated high blood pressure. So it might be time for lifestyle changes."

See the whole picture

Screenings have their proper place in healthcare, Rao said.

"Everyone needs screenings, but everyone's going to have different screenings," he said. "It goes back to this: Testing is more useful in people who are more likely to get the disease."

Everyone has a saved-by-screening story - a neighbor or relative who got tested for blood pressure or heart disease and then got a triple-bypass two days later that saved their life. Screenings absolutely have a place in medical diagnosis, Ware said. But keep things in perspective.

"The key is that people have to look at the whole picture," she said. "There's a lot of things that keep you in good health. We just don't think screenings are a substitute for healthcare."