There are probably a lot of things that annoy doctors. Patients diving into symptom-tracking websites like WebMD and convincing themselves they have a dire illness is probably near the top of the list, but a more recent development is also raising their ire: At-home genetic tests that claim to provide insights into risks of diseases like cancer.

Home DNA tests are nothing new, but in recent years the companies that peddle the spit-in-a-vial tests have shifted from innocent pursuits like revealing hints of ancestry to more serious claims, like providing risk analysis for a person’s long-term health. That’s really bad news for doctors who have been flooded with patients demanding care for diseases they don’t even have.

As The Guardian reports, doctors have reached the point that they’re outright demanding action against the companies that produce the kinds of at-home tests causing such a stir.

The issue here is twofold. The first is patients seeking over-the-top preventative action in an effort to save themselves from health issues they don’t actually have. The Guardian report quotes a doctor who dealt with a patient who wanted breast-removal surgery because an at-home test told her she was at risk of a mutation that may have increased her risk of cancer.

The second issue is that the tests themselves are often flawed or just completely wrong. The patient who wanted her breasts removed received a lab test from her doctor that revealed she didn’t even have the supposed mutation the at-home test claimed she had. Her surgery was called off.

Depending on the country, at-home DNA tests have to abide by certain regulations. Some have come under fire, especially in the United States, for making unsubstantiated health claims without the authority to do so, while others offer vague, technically legal health guidance that can often raise more questions than it answers.

Put simply, don’t place your trust in a plastic vial sent through the mail. Genetic testing is cheaper than it’s ever been, but that doesn’t mean the at-home DNA test is the equivalent of a doctor, and should definitely not be treated as such.