When Christina Applegate looks back, she can recognize the signs. Filming a dance sequence during the first season of the Netflix wine-mom dramedy “Dead to Me,” she found herself off balance. Later, her tennis game began to falter. At the time, Applegate, an actress with an aversion to special pleading, didn’t make excuses. She had to work harder, she told herself. She had to try again.

“I wish I had paid attention,” she said during a recent video call from her home in Los Angeles. “But who was I to know?”

Over several years, the tingling and numbness in her extremities grew worse. And in the summer of 2021, on set for the third and final season of “Dead to Me,” she received a diagnosis. She had multiple sclerosis, an autoimmune disease that disrupts communication between the brain and body. Production shut down for about five months as she began treatment.

“There was the sense of, ‘Well, let’s get her some medicine so she can get better,’” Applegate, 50, recalled. “And there is no better. But it was good for me. I needed to process my loss of my life, my loss of that part of me. So I needed that time.”

“Although it’s not like I came on the other side of it, like, ‘Woohoo, I’m totally fine,’” she added. “Acceptance? No. I’m never going to accept this. I’m pissed.”

This was on a recent morning. Applegate was sitting up in bed — her happy place, where she watches reality television. (“That’s my meditation,” she said.) She had pulled her hair into a scrappy bun. Black glasses sat astride her nose. And her resting face did have a certain indignant quality.

But she wanted to do this interview, because the last season of “Dead to Me” arrives on Netflix later this month, on Nov. 17.

“This is the first time anyone’s going to see me the way I am,” she said. “I put on 40 pounds; I can’t walk without a cane. I want people to know that I am very aware of all of that.”

In truth, her illness is nearly invisible onscreen — a feat of savvy blocking and Applegate’s talent and resolve. Still, she wanted to offer context.