Exclusive: Kristen Johnston Explains Upcoming Absence From ‘The Exes’

Jeremy Blacklow
Yahoo TV

If you've read Kristen Johnston's 2012 memoir "Guts: The Endless Follies and Tiny Triumphs of a Giant Disaster," you know that she's an actress who knows a thing or two about perseverance.

But even her drive to keep working through illness (as she documented in "Guts") couldn't help in her current battle. Johnston, 46, will be taking an upcoming two-episode break from her hit TV Land show, "The Exes," as she continues recovering from her recent diagnosis with an auto-immune disorder, which she's only now speaking about for the first time.

"I was vacationing at the Mayo Clinic in November for two weeks," she explains. "I've finally been diagnosed with an auto-immune disorder, where your immune system starts attacking healthy tissue. This has been way worse than anything that happened in 'Guts.'" [In her amazingly candid first book, Kristen describes her painful recovery process from an addiction to painkillers and alcohol.]

Although the two-time Emmy winner (for "3rd Rock From the Sun") shares that she's not in any pain, the disorder has left her almost completely unable to move. Activities like walking up stairs or lifting anything have been nearly impossible. She's even had to wear a neck brace around set.

"I've been really really sick since September," she shares in a note posted Tuesday to her Twitter account.

"It's an inflammation of my skeletal muscles," she elaborates to omg!. "A pain is something people can understand, but it's not pain; I just couldn't lift my arms, and I could barely walk.

"The brutal honest truth is that around early September I was having trouble walking up stairs. Within two weeks I was at a screening of a film that I'm in and I couldn't walk up the five stairs to the stage [to talk with the crowd]. So I went to my regular doctor and got a blood test."

[Related: Brandon Routh Is Coming to 'The Exes']

However, there's good news on the horizon. Although getting a correct diagnosis took some time, she's now on the up and up. "I really am getting better now," she notes. "I'm on a great treatment with a top immunologist. I'm just a little bummed though at the four months, 17 doctors, and two weeks at the Mayo Clinic to finally figure out what was wrong with me. As usual my timing was perfect. But … thank God for Leah Remini!"

Just a few weeks ago, TV Land announced that Remini would be joining the "The Exes" for a multi-episode arc, playing Stuart's (David Alan Basche) recently divorced sister from Staten Island. Although Kristen's character (Holly) will overlap for a few episodes with Leah's character (Nicki), it's clear now that Leah was brought in to help during Johnston's recovery. Leah's taped one episode so far, and Kristen will appear briefly in her second episode, which tapes this Wednesday and in which their characters meet for the first time.

"Her first episode airs Jan. 1 and it's hilarious, I've seen it," says Johnston.

"I'm just missing two episodes. I'm back in an episode [shooting Wednesday] night for one scene. In another episode, you'll see me sitting for the whole time. It's been really hard on the writers who have had to scramble. I'm the kind of girl that when I have the flu when I'm doing a play, I throw up off stage and then get back out there. I couldn't do that this time."

Here's wishing one of Hollywood's funniest working actresses a speedy recovery and a healthy 2014!