While Washington is deep in the throes of trying to overhaul the nation's health-care system, another development is fast gathering momentum that shows the lawmakers in many ways are pursuing a moving target.

A growing number of Americans are bypassing doctors and going directly to online and storefront labs for diagnostic testing. Most often they pay for these tests out of their own pocket. The results may persuade the consumer to pursue the matter further with a personal physician but, in any case, the consumer is in charge of who sees the results.

So far, the testing is generally basic stuff - sex, drugs and cholesterol - with sensitive privacy issues. The labs can test for STDs and paternity. Job seekers can find out whether they'll pass the pre-employment drug test many companies demand. And the labs can test the DNA of evidence brought in by a suspicious spouse.

The name of one fast-growing chain of walk-in labs encapsulates the field's business model, Any Lab Test Now. The company says it can generally have testing results within 24 hours and at a cost that is as much as 80 percent less than going through a doctor. The lab franchises offer up to 1,500 tests, from a simple cholesterol check to more sophisticated packages of tests that address complex medical issues.

Medical testing is a $55 billion-a-year business and lab testing sold directly to consumers accounts for only $100 million of that market, but it is set for rapid expansion because of cost, convenience and a growing sense that people need to be their own health advocates.

The medical profession views this development with some skepticism, fearing that consumers will order the wrong kinds of tests or misdiagnose the results. Major physicians organizations like the American Medical Association have cautioned against any kind of clinical or genetic testing done without a doctor's consultation.

There is no federal oversight over medical testing other than requiring that the labs that do the actual testing for the storefronts be properly certified. State regulations vary widely. As so often happens, the consumers seem to be far out in front of the lawmakers and regulators.