Christina Applegate has opened up about the difficulties of living with multiple sclerosis, and the signs of illness — such as numbness and a tingling sensation in her limbs — that arose years before her formal diagnosis. 

“I wish I had paid attention,” she said during an interview with the New York Times published Tuesday, “But who was I to know?”

Applegate recalls feeling off-balance while filming her Emmy-nominated Netflix series, “Dead To Me,” and struggling during a tennis match before receiving an official diagnosis while on the set of her show. Production shut down for nearly five months as she began treatment for the disease, according to the Times.

“There was the sense of, ‘Well, let’s get her some medicine so she can get better,'” the actress said. “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.”

Moderator Alyssa Mastromonaco, Christina Applegate, Linda Cardellini and creator Liz Feldman attend “Dead To Me” #NETFLIXFYSEE For Your Consideration panel discussion at Netflix FYSEE on June 3, 2019, in Los Angeles, California.

Amy Sussman via Getty Images

While there was a question as to whether filming of “Dead To Me” would be able to resume, Applegate insisted on pushing through by using a wheelchair to get to set and having a friend occasionally hold her legs off-camera. Some changes were even made to the script to accommodate energy and stamina levels during filming.

“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,” said Applegate. 

MS affects nearly 1 million adults in the U.S., and can be disabling. Most people receive an MS diagnosis between the ages of 20 and 40 and the disease is more common in women than men, according to the Cleveland Clinic, a nonprofit academic medical center. Symptoms can include numbness or weakness in the limbs, electric-shock sensations that occur with neck movements, or tremors. MS can also affect vision and speech, cause dizziness and fatigue, and in cases like Applegate’s, impact one’s general mobility.

There is no known cure for the disease. But according to Mayo Clinic, treatments can help to speed recovery after attacks.  

Applegate has been transparent on Twitter about her difficulties living with MS, showing photos of the assistive devices she uses to walk, chronicling the insomnia that’s accompanied her diagnosis, and even showing love to a fellow Hollywood star Selma Blair, who was diagnosed with the disease in 2018. 

Blair, who was a contestant on the current season of “Dancing with the Stars,” said that recent MRI results prompted her to leave the show, citing “bone trauma and inflammation among rips and tears” that could worsen with continued movement. Blair published a memoir that delves into her illness, titled “Mean Baby,” earlier this year.

In 2021, Blair starred in a documentary that chronicled her worsening health after her diagnosis, “Introducing, Selma Blair.” Applegate lauded Blair for her transparency, she wrote, “My girl Selma Blair documented the first year. Which is hard.”

“Being technically disabled is what it is,” Applegate tweeted. “I didn’t know what MS was before I had it. My life is changed forever.”

Caitlin O’Kane contributed to this report.