Multiple sclerosis (MS) is an autoimmune disease that impacts the brain and spinal cord. These are the main components of the central nervous system. The central nervous system controls nearly everything we do, from walking to doing a complex math problem.

MS can manifest in many different types of complications. It affects the coverings of nerve endings within the central nervous system. This can result in diminished vision, motor function, tingling, and pain in the extremities.

MS can be a challenging condition, but many people with the disease lead healthy and active lives. Here’s what some celebrities have to say about living with MS.

Joan Didion is an award-winning American author and screenwriter. Known for her vivid descriptions, biting irony, and candor, Didion wrote about her diagnosis in “The White Album.” The essay is from her nonfiction collection “Slouching Toward Bethlehem.” She wrote, “I had … a sharp apprehension of what it was like to open the door to the stranger and find that the stranger did indeed have the knife.”

Didion’s work was a channel for the uncertainties she felt while adjusting to her condition. At 82, Didion is still writing. In 2013, President Obama awarded her the National Medal of Arts and Humanities.

Rachel Miner is an American actress who is best known for her portrayal of Meg Masters in The CW Network series “Supernatural.”

Miner spoke out about her diagnosis at the Dallas Comic Convention in 2013. She continues to manage her symptoms, but in 2009 had to leave the show due to the physical complications of MS. “The physical constraints were at the point that I feared I couldn’t do Meg or the writing justice,” she told a fan blog.

Although she maintains she didn’t officially leave the show because of the disease, she also asserts the importance of knowing your limits and listening to your body.

Jack Osbourne, son of British rock star Ozzy Osbourne, was introduced to American audiences in the early 2000s as a teenager on the MTV reality show about his family. He publicly announced he has multiple sclerosis in 2012.

Since his diagnosis, Osbourne’s motto is “Adapt and Overcome.” He uses the hashtag #Jackshaft on Twitter to talk about his experience with MS. “I will never say that I am thankful for MS,” he said in an open letter. “But I will say that without MS, I don’t know if I would have made the necessary changes in my life that have changed me for the better.”

At age 26, country music star Clay Walker received a diagnosis of relapsing-remitting multiple sclerosis after experiencing tingling and twitching in his face and extremities. Walker says he struggled after he was first diagnosed: “I realized that I needed to stop dwelling on being diagnosed with a chronic disease, and instead focus on finding a groove.”

He spent some time working with his neurologist. And with the help of his family, he’s settled into a routine that enables him to better manage his symptoms.

Activism is one important component of Walker’s routine. He started Band Against MS, an organization to help educate others with MS.

Ann Romney is the wife of politician Mitt Romney. In her book “In This Together: My Story,” she shared that her life changed in 1997 when she was diagnosed with MS. Since then, she works hard not to let her condition define her.

“Finding joy in your life is another really important component,” she said in an interview with PBS. “And losing yourself in doing something else, and not always dwelling on your illness is very important.”

“The Sopranos” star was diagnosed with MS in 2002 at just 20 years old. She didn’t make her diagnosis public until 2016 after becoming a new wife and mother.

Today, Sigler wants to be an MS advocate. “I think a lot of the time when people are dealing with any chronic illness you can feel very isolated, you can feel alone, you feel like people don’t understand,” she said in an interview. “I wanted to be somebody that says, ‘I get it, I feel you, I hear you, I go through what you go through, and I understand.’”

She shares personal experiences on Twitter, using the hashtag #ReimagineMySelf.

She’s also partnered with Biogen on the Reimagine Myself campaign, which seeks to show how people living with MS lead fulfilling and productive lives.

Richard Pryor gets credit for being a source of inspiration for many of today’s most successful comedians. In the last three decades, he has widely been recognized as one of the greatest comedic voices of all time.

In 1986, Pryor received a diagnosis of MS, which slowed his comedic career until he retired for health reasons. In 1993, he told the New York Times “… I do believe in God and the magic and the mystery of life, it’s like God says: ‘You slow down. So what you walk funny. Take five.’ And that’s what I’m doing.”

He died of a heart attack in 2005 at the age of 65.

Former first lady of the United States and health and fitness advocate Michelle Obama’s father lived with multiple sclerosis. During her 2014 Reach Higher campaign, Mrs. Obama toured high schools throughout the United States and spoke candidly about witnessing her father struggle with MS. “Seeing my father in pain, seeing him struggle, watching that every day, it broke my heart,” she said. Mrs. Obama credits her father as her inspiration to achieve the success she enjoys today.

Gordon Schumer is the father of comedian, actress, and writer Amy Schumer. He received a diagnosis of MS in middle age. Colin Quinn portrayed him in Amy Schumer’s 2015 debut film “Trainwreck.” Schumer speaks and writes frequently about her father’s battle with the disease, so much so the MS community now recognizes her as an important activist. She cites her father’s good sense of humor and biting sarcasm in the face of his condition as inspiration for her own comedy. “I love to laugh. I seek laughter all the time. I think that’s something that also comes with having a sick parent,” she said in an interview.

Hollywood and the media have long struggled to accurately portray people with disabilities. But the long-running political drama, “The West Wing,” seems to have gotten it right.

The main character, President Josiah Bartlett, has MS. The show chronicles his tribulations with the condition as he juggles his very successful political career. The National Multiple Sclerosis Society gave the program an award for its depiction of the illness.

Jason DaSilva is an American documentarian and creator of “When I Walk,” a documentary that follows his life after his diagnosis at age 25. DaSilva has primary progressive multiple sclerosis. Unlike other forms of MS, primary progressive MS has no remissions. He started filming his life to capture all of his triumphs and struggles, embarking on a new life as a filmmaker. As a wheelchair user, he uses his platform as a documentarian to address the stigmas of disability. His work helps him cope with the challenges of MS. “It is all about freedom,” he told New Mobility. “As long as I can keep doing things creatively, or making things, I’m OK.”