In today's health matters, U.S. Researchers say more than half of healthy women who undergo an annual mammogram will get at least one false positive over a ten year period.

Analysts looked results from more than a 160,000 U.S. Women. They found more than half had a false positive in a ten year period. And between seven and nine percent would have a biopsy that didn't find any cancer.

The risk of a false positive was about the same for women in their 40s or 50s. However women who started screening in their 40s had a higher risk over their lifetime of having that false positive.

Study authors say the findings should be used by doctors to help women make an informed decision about mammograms. They added women should know the risk of false positive tests results and knowing may relieve some anxiety about results.