If you had to go to the emergency room, you would be lucky if a nurse like Dana Evans, from HBO Max’s “The Pitt,” were assigned to help you.

Part coach, part caretaker, Charge Nurse Evans, played by the veteran actress Katherine LaNasa, is a woman who has seen it all and solved it all. And she still manages to be the wind beneath the weary wings of Noah Wyle’s emergency room doctor, Michael Robinavitch.

John Wells, an executive producer of the series, calls her “empathetic and tough.” Audiences, specifically nurses, have lauded her performance as capturing the profession accurately.

For LaNasa, 58, the role is unparalleled, the part she was meant to play and the one that has earned her the first Emmy nomination of her 30-plus year career. It is also the one that came into her life at after a particularly fallow time, when the acting roles were scarce and she had recently finished her treatment for breast cancer.

“It’s nice when something like this happens, when you’re an older person,” LaNasa said about the Emmy nomination. It was a warm summer day in Burbank, and she was seated cross-legged and barefoot on her dressing room couch on the Warner Bros. lot, where she is currently shooting Season 2 of “The Pitt,” premiering in January. She looked glammed up and youthful, nothing like the out-of-work actor battling cancer she had recently been.

“I love acting, but also I’m very formed; I’ve been through experiences,” she said. “I’ve sat at the bedside while people died. I’ve given birth. I’ve raised children. I’ve had cancer. So you know, this is just a nice thing.”

“Nice” may be code for previously unfathomable. Born and raised mostly in Louisiana by a father who was a flight surgeon in Vietnam and a mother who went to nursing school, LaNasa’s career has spanned a wide range of genres, mediums and popular appeal.

She played the wife of Will Ferrell’s congressman in the political satire “The Campaign.” She played the podcast producer to Octavia Spencer’s investigative reporter in the Apple+ show “Truth Be Told.” She has appeared in “Seinfeld,” “E.R.” and “Gray’s Anatomy,” and yet she gets recognized in public most often for her four-episode arc in “Two and a Half Men,” she said, in which she played the girlfriend of Charlie Sheen’s character.

A role playing Robert Duvall’s daughter in “Jayne Mansfield’s Car,” directed and co-written by Billy Bob Thornton, should have made waves; instead the film died with critics and barely received a theatrical release. In a “six degrees of separation” matchup, she could rival Kevin Bacon — who, as it happens, also starred in “Jayne Mansfield’s Car.”

“I’ve done big time projects with really great auteurs, and nothing’s happened with them,” she said. “On one level, those jobs gave me great confidence. I’m doing a comedy with the top comedy guy and doing this drama with the top drama guy.

“But on the other side, not ever being on a hit or always getting rejected because you’re not enough of a name for things, you sort of think that’s your station.”

Indeed, before “The Pitt,” few were likely to have known her name or her expansive résumé — and even fewer her wild introduction to Hollywood.

A company ballerina as a teenager, she was flung into the world of Hollywood in her early 20s, when a chance meet cute with Dennis Hopper, fresh off an Oscar nomination for his role in “Hoosiers,” turned into a whirlwind romance that introduced LaNasa to the world of acting (and a three-year marriage that produced a son).

It also taught her that Hollywood has no center. Even at the top of your game, you’re clamoring to stay relevant.

“I would go to dinners at Roddy McDowell’s, and there would be Lauren Bacall and Bette Davis and Liza Minnelli. It was bananas,” she said. “I also got a whole education. There is no there there. People at the top feel rejected and not good enough and slighted, and they’re still having to scrap. You’re at the top for the very little moment that you’re at the top.”

When she was younger, television comedy writers thought of her as “a unicorn,” she said — a glamorous girl with a weird sense of humor. But network executives wanted one or the other, never both.

“When I was coming up, it was like, you can be Mary or you can be Rhoda, but Mary can’t be weird,” she said.

With “The Pitt,” things were different. The audition process wasn’t difficult. She seemed to understand the character at a root level, imbuing her with a quiet confidence that impressed the show’s producers from the start. The character breakdown for Dana defined her as someone who is “smarter than all the doctors and isn’t afraid to let them know,” a detail LaNasa didn’t read before going into the audition.

Instead, she was compelled by the nurturing aspects of the character, showing up to her video meeting looking, according to Wells, “like she belonged there from the beginning.”

“She played it as somebody who’s been through a lot of life and still shows up every day — and has compassion in ways that, I think, many of us would not be able to have compassion, day after day, in these settings,” he said.

Some of that arose from the challenges in LaNasa’s own life. Just six months before she began filming “The Pitt,” she was still in and out of the hospital, dealing with the side effects of cancer radiation treatment. It had her interfacing with doctors and nurses more frequently than she had her entire life. Work was slow, and her husband, the actor Grant Show (“Melrose Place”), was also dealing with health issues.

“It was literally like a plague on the house,” she said. But it was experience she drew from.

The role of Dana also allowed her to exploit her dance background, which helped her to master the choreography required in a show that tries to mimic the frenetic environment of an understaffed, overpopulated emergency room. Added up, the circumstances made landing this role, at this moment, feel like the result of some “spiritual equation,” she said.

“The whole thing has been everything that I love,” LaNasa said. “It’s super physical; it’s a complex role. I get to be like a real woman. I don’t have to wear 100 pairs of Spanx and feel like I have that idealized female pressure on top of trying to do acting. It’s just a really great vibe.”