Fitbit has built its business around tracking users' steps and heart rate.
But with the company's stock price down 62 percent in the past year and Apple threatening its market leadership, Fitbit's future might be predicated on its success in the medical sector.
Fitbit is building tools to help diagnose and monitor sleep apnea, a disorder that affects some 18 million American adults, the company told CNBC.
Sleep apnea is characterized by pauses in breathing and shallow breath and comes with an increased risk of heart failure, obesity and strokes. One of the biggest concerns is that a lot of people don't realize they have it.
"We'd perform a useful public service by alerting users to the fact that they have a problem," said Conor Heneghan, Fitbit's lead research scientist, in an interview. Heneghan works on Fitbit's research and development team, which is focused on testing out new biomedical sensors and exploring potential applications.
Sleep apnea is also a big potential market, with revenue expected to increase to $6.7 billion by 2021 from $4.6 billion last year, according to Research and Markets.