MINNEAPOLIS — Halfway through her fifth year of teaching high-school English, Anita Shreve paused.

“I had this panicky feeling that I had to start writing,” she said. “I don’t remember the exact circumstances — I just knew that it was now or never.”

She picked “now,” boldly quit her job, and began to write short stories. Her rash decision eventually turned out pretty well — for herself, as well as for her millions of loyal readers — but at the time her future was not at all sure. She published a few stories, but many more were rejected. “Past the Island, Drifting” eventually won a prestigious O. Henry Award, but by then Shreve had moved on to journalism, figuring, she said, “you couldn’t actually make a living writing short stories.”

Over time, Shreve has, however, made a comfortable living writing intense, thoughtful novels — one every 18 months or so — about relationships and grief and the peculiarities of chance. Her 16th novel, “Rescue,” came out last week, and previous books have been bestsellers. “The Weight of Water” was shortlisted for the Orange Prize; “The Pilot’s Wife” was an Oprah pick in 1999. Both books, as well as her novel “Resistance,” were made into movies.

Shreve grew up in Dedham, Mass., outside of Boston, and attended Tufts University. Her father was a pilot, her mother was a homemaker, and Shreve had two little sisters. She spent a lot of time outdoors, playing made-up games, or inside, reading books from the library.

“I had a happy childhood, very inventive,” she said recently. “The biggest difference between childhood then and childhood today is that then you had to rely on your ability to invent, and your imagination.”

But writing? “You wouldn’t have mentioned it in our household. It was absolutely not an idea. We were so far removed from that universe.”

Somehow, though, the desire crept up on her. After leaving her teaching job to write, Shreve and a friend planned a trip to Kenya, where she ended up working for a magazine for African women called Viva.

Upon her return to the United States she worked briefly at American magazines and then began freelancing for the New York Times magazine and elsewhere. “I turned two of those (freelance) stories into books, nonfiction books,” she said. “And while I was writing one of the nonfiction books, I started to write, in secret, my first novel.”

Shreve’s second run at fiction was done privately because she had been warned against it. “I had said to my agent, ‘I think I could write a novel,’ and she said, immediately, ‘Don’t. If you can make a living — and you’re making a decent living writing nonfiction — don’t, don’t, don’t.'”

Shreve read Alice McDermott’s “That Night” as her daughter played on the floor, and then she sat down and wrote a 10-page outline for “Eden Close,” which was not just published but is still in print more than 20 years later.

She no longer outlines her books in quite so detailed a manner, beginning, instead, with “a really great idea” and then writing every morning on a legal pad, “in my bathrobe, in longhand, in a tiny little corner of my office,” an upstairs room that looks out over the Atlantic Ocean. Four hours is usually enough for one day. “You can tell. This is one thing I have learned over the years — you really know, to the sentence, when you’re done.”

Her novels are set in places that Shreve herself knows well — upstate New York, and small towns in the Northeast. “Rescue” is about Peter Webster, a lonely and hardworking paramedic in Vermont. The small-town setting, she says, allows her to show Webster’s entire life — his parents, friends, neighbors and values — in a way that a book set in a big city cannot. “The place,” she said, “is always as much a character as the other characters.”

“Rescue,” in which an unlikely romance first blossoms and then withers, is studded with scenes in which Webster and his colleagues take blood pressures, restart hearts, load patients into ambulances, extricate victims from crumpled vehicles wrapped around trees.

To prepare for “Rescue,” she spent many hours with an EMT who coached her through the details of the job and then read scenes as Shreve wrote them. “We would brainstorm, and then she would tell me the correct language — he wouldn’t say this, he would say that, or, you wouldn’t do that first, you’d do this first.”