It’s the season to get outdoors in New England, and, unfortunately, that also means it’s Lyme season. The CDC estimates about 300,000 people annually contract Lyme, mostly here in the Northeast.

Many doctors want to test patients before diagnosing them with Lyme — and a recent federal study found there are roughly 3.4 million Lyme tests conducted in the U.S. each year. But how accurate are they?

"Lyme is the boogeyman of the Northeast, attacking when people are doing what they love most: gardening, hiking, camping," said Wellesley resident Brandi Dean.

Dean thinks a tick carrying the disease bit her while she was watching her husband's team play soccer on a field near some woods.

"I had heart palpitations, severe panic attacks, dizziness, I was losing my hearing, numbness on the right side of my body and vertigo," she said.

But Dean didn’t have the most common telltale symptom of Lyme: a rash that looks like a bullseye. So doctors told her she probably didn't have the disease.

"I felt like no one believed me and it was awful," she said. "I just felt ignored, completely ignored by the medical community."

At the time, Dean was five months pregnant with her second son.

"I went to ten other doctors after that," she said. "And I had three positive validated tests and several doctors were totally disregarded my positive tests.”

It’s difficult for tests to detect Lyme disease in its early stages. Dean discovered that mainstream doctors believe even federally recommended Lyme tests aren't perfect. Despite that, she was lucky — her doctors agreed to treat her for the disease.

Others in Dean's situation aren't as lucky. In an effort to prove their condition, they seek out doctors willing to use Lyme tests that haven't gone through an FDA review.

Those tests can legally be offered by certain labs nationwide because of an exemption in federal regulations created in the 1970s.

New York is the only state that rigorously analyzes the tests to ensure they work. The New England Center for Investigative Reporting found that over the last decade, New York officials have prevented seven U.S. labs from selling Lyme tests in that state.

"The real problem is it because it's only being done in one laboratory — nobody really knows whether this test really works or not and whether or not it is helpful diagnosing the disease that it's directed at," said Andrew Onderdonk, a professor of pathology at Harvard Medical School who was diagnosed with Lyme disease in 2012 using a federally recommended test. Onderdonk runs the Clinical Microbiology Lab at Brigham and Women's Hospital. He says there's a reason some labs don't go through the process of earning federally recommended status.

"They are making money; they don't want to go through the expense of going through a true validation," he said.

Researchers say that, yes, FDA validation doesn’t mean a test is — but it does mean the test’s limitations and faults are known factors. The same can’t be said for unvalidated tests, which often aren’t covered by insurance and can cost as much as $1,000.

NECIR found labs selling unvalidated tests include a Pennsylvania company cited by New York regulators in 2012 for "substandard" scientific practices. Another lab in Wisconsin is owned by a convicted felon sentenced in 1992 for his role in a malaria research fraud case. Officials at both labs say they stand by their tests.

Onderdonk says he understands why people would use unproven tests.

"It's a very painful disease and people who have gone to their primary-care physicians, who are tested by the traditional method, who are negative, are desperate to be diagnosed because Lyme is in fact a treatable disease," he said.

Some doctors defend their use of non-FDA recommended Lyme tests, including Minnesota physician Chris Foley.

"As far as I'm concerned the FDA is hardly the litmus test I would use," he said.

Foley says he trusts the scientists who developed the Lyme tests he uses.

"It can provide me with just another tool to manage Lyme patients, and over the last two years I have found it to be unusually accurate for patients who may exhibit signs of recurrent illness and can be proven to have nothing else," he said.

Some patients diagnosed with Lyme through unvalidated tests go on to receive treatment — often antibiotics, including doxycycline, administered over months or even years. And many they say they feel better afterward. But that doesn't necessarily mean they had Lyme disease, says doctor Fred Silverblatt. He runs a Lyme clinic at South County Hospital in southern Rhode Island.

“People will say, 'Because I get better on doxyclycline, therefore it must be Lyme Disease,'" he said. "They use that as a diagnostic test when in fact lots of other things are treated with doxyclycine and in fact, doxycycline has other effects, such as an anti-inflammatory effect that could mask other possible diagnoses."

Dean is now trying to wean herself off antibiotics that have alleviated her symptoms. She also runs a support group for Lyme patients.

"I don’t think any of us has confidence in the tests that are available to us now, which is very unfortunate, because I think once you are able to diagnose the illness you can help treat these people who are very sick," she said.

Until then, Dean says she’ll do what it takes to feel better, even if it means more treatment.

Reporter Beth Daley discussed the findings on Greater Boston: