(CBS) -- "I wanted to see if I had the Alzheimer's gene because that runs in my family," said Sara Altschule.
Instead, her test revealed she carried a BRCA gene mutation, greatly increasing her risk of breast cancer.
"It's just a lot to process because one day you think you're healthy, and then you're still healthy but you have this really high risk."
A follow up with a genetic counselor confirmed her results.
"My cautionary note is, Do you really want to know?" said Dr. Gail Vance with the College of American Pathologists.
Vance says while these popular tests can be potentially life-saving, consumers need to ask some serious questions first.
"This might be information for yourself, but truly it's information for your family as well. And maybe your family members don't want to know about this."
Vance also stresses following up with your doctor to interpret the results.
"Say, 'Okay. you know me. You have all my numbers and the charts. How does this fit into my healthcare plan?"
Sara chose to have a preventative double mastectomy over the summer.
"Now my chances of developing breast cancer is under 1%," she said.
She's sharing her journey on social media
"I decided to talk about the good, the bad, the ugly through all this to help people understand what it means to have the mutation, to help other women."