DOCTORS ARE frequently criticized for the things they fail to do. In general, they don't spend enough time on patient education, don't provide adequate preventive care and don't treat many chronic disorders aggressively enough.

These shortcomings are well-documented. An equally important problem that attracts less attention, however, is doctors who do too much. Whether it's ordering an unnecessary test or advocating an aggressive form of treatment over one that's more measured, the result is the same. Patients wind up getting more than they need.

Forty-two-year-old Katie Jacobs of Los Angeles learned that lesson during a recent visit to the gynecologist. Based on her Ashkenazi Jewish heritage and the fact that her grandmother had had breast cancer, both of which could increase her risk of developing the disease, he encouraged her to get tested for the breast cancer genes.

"It was the last thing that I expected," Jacobs recalls. "And actually quite scary."

The test probably wasn't warranted. The U.S. Preventive Services Task Force recommends against routinely referring women for genetic screening for BRCA1 and BRCA2 (the so-called breast cancer genes) unless their family history shows a strong risk for carrying them. According to the task force, even for an Ashkenazi Jew, having just one grandmother with breast cancer isn't enough to merit testing.

Such medical "overtreatment" is commonplace. For example, the task force guidelines also recommend against using electrocardiograms as a routine screening test for heart disease, but that doesn't stop many doctors from referring their healthy middle-aged patients for them. The American College of Obstetricians and Gynecologists doesn't believe that low-risk pregnant women need multiple ultrasounds, yet many obstetricians perform several on all of their patients.

Aggressive medical care isn't limited to prevention and screening; it extends to medical treatment as well. Pediatricians are often quick to prescribe antibiotics to children with ear infections, but simply monitoring them often would be more appropriate (8 in 10 cases will, in fact, improve without treatment). Some orthopedists recommend shoe inserts, or orthotics, for their patients with flat feet, yet studies have found that almost 1 in 4 people have flat feet and that few problems arise if the condition is left untreated.

A number of factors are probably responsible for prompting doctors to overtreat their patients in these ways. In some cases, it's just a matter of practice style. "Faced with clinical uncertainty, some doctors would wait and watch," says Carolyn Clancy, director of the Agency for Healthcare Research and Quality. "Others, however, are more likely to take action."

Pressure from patients probably also plays a role. "Some people find this approach reassuring," Clancy says. When their doctors do a lot, they feel cared for and safe. Many patients prefer to be handed a prescription or sent for a test rather than hear that nothing needs to be done. They want no stone left unturned, even when -- on a scientific level -- it doesn't necessarily make sense to do so.

Some doctors may even be motivated by financial gain, standing to reap additional payments for the tests they perform.

Some people find it difficult to find fault with this "better safe than sorry" strategy -- after all, what's the downside to going the extra mile? But overtreatment can sometimes lead to more problems than it solves. The tests and interventions may themselves be risky; X-rays and CT scans, for example, expose patients to radiation, and medications can have side effects. Even those that seem exceedingly safe, such as blood tests, are not risk-free. They often produce false positive results, suggesting a problem even in the absence of one and causing tremendous worry for the patient.

And, because you can't ignore an abnormal test result, a positive result of any sort generally means more testing. "They trigger a diagnostic and therapeutic cascade," Clancy says. An abnormal stress test might necessitate a cardiac catheterization; a CT scan that reveals a density in the liver could lead to a liver biopsy.

An issue many people ignore is that of cost. Simply stated, overtreatment is expensive. Although many believe that cost shouldn't factor into treatment decisions, I would argue otherwise. It simply doesn't make sense to pay for things that don't work. Insurers may absorb the immediate expense, but eventually the costs are passed on to patients in the form of higher premiums.

After consulting with her internist, Jacobs decided that the genetic test wasn't necessary and skipped it. But then, several weeks ago, during a checkup, her dentist suggested a new screening test, called ViziLite, to check for oral cancer.

Jacobs had never heard of the test, however, the dentist presented a convincing argument. She would have liked to learn more about it before making a decision but because she wanted to save herself a trip back to the dentist, she agreed to the procedure. "It was only $75," Jacobs says. "I figured, 'What could it hurt?' "

She probably could have saved herself some money. The American Dental Assn. doesn't endorse ViziLite as a screening test for oral cancer.

Dr. Valerie Ulene is a board-certified specialist in preventive medicine practicing in Los Angeles. She can be reached at themd@att.net. The M.D. appears the first Monday of the month.