Actress Christina Applegate has revealed she’s been diagnosed with multiple sclerosis. 

The “Dead to Me” and "Married... With Children" star wrote in a Twitter post that she learned of the diagnosis a few months ago.

“It’s been a strange journey,” Applegate, 49, wrote. “But I have been so supported by people that I know who also have this condition. It’s been a tough road. But as we all know, the road keeps going. Unless some a****** blocks it."

“As one of my friends that has MS said ‘we wake up and take the indicated action,'" she continued in a subsequent post. "And that’s what I do. So now I ask for privacy. As I go through this thing. Thank you.”

Multiple sclerosis, or MS, is a potentially disabling disease of the central nervous system. In it, the immune system attacks the protective covering of nerves. People with severe MS may lose the ability to walk independently, or at all.

There is no cure for multiple sclerosis, but there are treatments that can help speed recovery after attacks, slow the progression of the disease and manage its symptoms.

Nearly 1 million Americans are estimated to be living with MS, according to a 2019 study.

This is not Applegate’s first serious health issue. In 2008, she was diagnosed with breast cancer and underwent a double mastectomy.

Applegate’s breakthrough role came as a teenager in the TV series “Married… With Children,” in which she played Kelly Bundy. She also has appeared in films such as “Don’t Tell Mom the Babysitter’s Dead,” “Anchorman” and “Bad Moms.”

Applegate won an Emmy in 2003 for "Outstanding Guest Actress in a Comedy Series" for her role in the hit sitcom "Friends." She was also nominated for a Tony award in 2005 for Best Actress in a Musical in a Broadway revival of "Sweet Charity."

She currently stars in the Netflix series “Dead to Me,” a role that earned her an Emmy nomination last year.