Want to know how many steps you took today? Fitbitcounted. How about the calories you burned on the elliptical? The machine tallied them for you. Need a pulse check? Here's an instantaneous readout. Consumer health products have become more sophisticated thanks to tiny computers packing lots of punch. Now the health-conscious can gorge on as much biometric data as they can handle.

Inside medical labs, the machinery — as you'd expect — gets increasingly complex. Troves of data are now produced by sophisticated testing. Scientists can detect tumors at their earliest stages, sequence entire genomes, and — controversially — identify genetic markers and predispositions before they have a chance to manifest as health problems.

With an ocean of on-demand data available to us, and to our doctors, when does all that information become too much? And, how much do we want to know when our health takes a turn for the worse?

"If there's something actionable, something you can really do to prevent the disease, there's a strong case for getting the person to know. You wouldn't force them to know, but you'd really try to persuade them to know," medical ethicist Art Caplan said Wednesday on Boston Public Radio.

Caplan, who is head of the division of medical ethics at NYU's Langone Medical Center, said in certain cases advanced medical data dictate the need for immediate action. "When newborn babies are born, we test them because certain diseases, (...) if you get them on the right diet, (...) they do okay," Caplan said. "When there's nothing to do, I think it's up to the individual" to decide if they want to know.

Caplan said tricky ethical considerations have arisen with the advent of DNA testing. "We had a guy come in for testing for Huntington's disease, and I got a call from the lab," Caplan recalled. The test was negative, but a new wrinkle emerged. The lab technicians told Caplan, "'Here's the problem — the guy who he thinks is his father isn't his father,'" Caplan said. "We didn't tell him, because we decided he came in to find out [whether] he was at risk, and he's not at risk, and we let it go."

When a patient tells her physician — against the doctor's advice — she doesn't want to know about, or treat a curable health problem, the physician can be put in a bind.

"We get that every once [in a while]" Caplan said of the so-called "ostrich effect." "I think you have to respect it, but you keep trying. Even if you lose on the first visit, you try a revisit. Lose on that one, you try again. So you keep nagging, basically."

Nobody wants to hear bad news, especially when it's a delicate subject like personal health. But when the upside is better health, and the chance to revert to a state of blissful ignorance after the treatment, maybe patients should listen a little more.

>> To hear the entire conversation with Art Caplan, click the audio link above.