Millions of people have sleep apnea, a potentially serious sleep disorder in which breathing repeatedly stops and starts. But most of them go undiagnosed. Those missed diagnoses cost an estimated $150 billion a year in the United States alone from things such as lost productivity and car accidents, according to the American Academy of Sleep Medicine.

So how do you reach more people at risk for the disease? Alphabet's Verily, its health unit, is spinning out a new company along with ResMed, a public company that specializes in sleep apnea and chronic respiratory diseases, to do just that.

Both companies are investing an undisclosed amount in the as-yet-unnamed venture, and is focused on sleep apnea and other sleep breathing disorders. This is not the first time that Verily has partnered with a life sciences company for a joint venture: It is also working with Johnson & Johnson on an effort called Verb Surgical to develop a next-generation surgical robot.

"The most important piece is really understanding and raising awareness around what a big problem this is," said Verily's chief medical officer Jessica Mega, in an interview with CNBC. "And then it's to identify people earlier and in the long-run really help this group."

An estimated 22 million Americans have sleep apnea, with about 80 percent of them unaware that they have it. It's associated with an increased risk of cardiovascular disease, obesity and diabetes, and it can also be dangerous for undiagnosed sufferers who experience a lot of fatigue during the day. Those who have it often wake up feeling like they're not well-rested after a full night's sleep. Other tells are loud snoring and interrupted breathing in the night, according to Jason Graff, medical director for sleep disorders for St Luke's Health System in Kansas City, Missouri.