For Julie Hadduck, a smartphone app that could diagnose cancer seemed like a miracle.
Her husband died of skin cancer in 2010. She worried that her three children could also be at risk, so she took them to a dermatologist twice a year.
When Hadduck photographed one of her daughter's moles, the app offered a diagnosis within seconds. "It came back red, and I was freaked out," said Hadduck, who lives in Pittsburgh.
She took her 9-year-old to a dermatologist, who reassured them the mole was benign. Hadduck, 47, deleted the app.
The app that Hadduck tried is one of more than 165,000 involving health and wellness currently available for download — a blending of technology and healthcare that has grown dramatically in the last few years. Experts see almost unlimited promise in the rise of mobile medical apps, but they also point out that regulation is sometimes lagging the pace of innovation, which could harm consumers.
"It's clearly a net positive, but I think there are risks to it," said Dr. Karandeep Singh, a professor at the University of Michigan who recently evaluated the quality and safety of hundreds of mobile health apps.
Major changes in the healthcare system set in motion by the Affordable Care Act, passed in 2010, coincided with the proliferation of smartphones. From 2013 to 2015, the number of health and fitness apps available on Apple's mobile operating system increased by 106%, according to one report.
Some of the most popular apps include Plant Nanny, a reminder to drink water; Sworkit, a personalized exercise video player; and HeartWatch, a heart rate tracker that's hooked up to the Apple Watch.