“Sometimes we wait for a diagnosis to know what to do,” Sigler said during a recent episode of the “Messy” podcast she co-hosts with Applegate.

“I’ve been struggling with a lot of fatigue for the past couple of months, and I was just convinced it was the MS … and then I got some bloodwork done, and my iron was so low.”

She’s now starting medication and realizes the low iron explains her exhaustion and hair loss.

“So not everything is your diagnosis,” she said, adding that she encourages Applegate.

Applegate spent years on infusion therapy. About two years ago, her doctor took her off treatment to watch her B cells, and when they didn’t change, that set off a review of her diagnosis.

The review concluded she doesn’t have MS, but the news didn’t bring relief.

“I’m back at square one. Congratulations. You don’t have MS. I was like not happy at all,” Applegate said on the “MeSsy” podcast episode, released Oct. 20.

Losing the diagnosis hasn’t taken away her pain, fatigue, or mobility problems, and her doctors now plan to investigate what has been driving her symptoms since 2021.

Both women know what it’s like to live with a serious diagnosis. Applegate was diagnosed with breast cancer in 2008, at 36, and had a double mastectomy.

Sigler has lived with MS for more than two decades and says it still drains her regularly.

Learning to Ask for Help

Sigler admits that asking for help was one of her biggest hurdles and one of her greatest lessons learned amidst her multiple sclerosis journey.

“I find that people in general, especially women, have a hard time asking for help,” she says.

“For me, asking for help, I thought, would reveal I was weak, incapable, and less than, and none of that was true, and the only way I was able to learn that was to start asking for help.”

“By letting people in, I learned my strength, power, and what I bring to the table. We all have strengths and weaknesses, but we all support each other; that’s the village. I’m unashamed to ask for help at any moment that I need it.”

Dr. Nancy Sicotte, who leads Neurology and MS/Neuroimmunology at Cedars‑Sinai, says earlier diagnosis and modern disease‑modifying therapies are allowing more patients to live stable, functional lives. These treatments can slow progression, reduce relapses, and limit new nerve damage.

She explains that updated diagnostic criteria now make it possible to identify MS before symptoms appear, based solely on imaging. “We can actually diagnose someone as having multiple sclerosis before they’ve even had a symptom,” she says — a shift that opens the door to intervening earlier than ever.

“If you can diagnose someone at that stage and start a disease‑modifying therapy, they may never develop symptoms or disability,” she adds, noting the potential to prevent clinical MS from emerging at all.

“MS Didn’t Define Me”

“MS didn’t define me, and when [people around me] looked at me, they didn’t see MS,” Sigler explained. She added that they saw a great friend, a great mom.

“It took time for me to finally believe what they’re saying.”

MS also crept into Sigler’s perception of her as a mom, at least early on.

“Being a mom is the one area I’ve felt the most insecure about my MS because I’ve been insecure about the physical limitations that would take away my value to my children as a mom,” she says.

However, over time, she learned that love, not physical ability, is what means most.

“Do not let a diagnosis define you. I know my kids feel loved, cared for, and supported, and hopefully that’s enough.”

Advice for Anyone Newly Diagnosed

Sigler knows the fear that comes with a new diagnosis, and she speaks directly to those standing where she once stood.

“If you’re newly diagnosed and you’re scared and feel alone, I see you. I get it. That is a very real thing to feel,” she says.

“It’s important to allow space for those emotions to fly through you because they’re imperative to your healing.”

The healing begins both inside and outside the hospital setting. Navigating treatment can feel overwhelming, Sigler admits.

“Really mapping out what your needs are and how this will fit into my life. What specifically do I need? The questions to ask after a diagnosis to your care team.”

Sigler also highlights the power of acceptance.

“Acceptance doesn’t mean you have to like the situation you’re in, but the only way to move forward is through acceptance. There are online support groups, podcasts like mine, and there are so many resources out there for people to find the community that they need.”

Sigler regularly opens up about the realities of living with MS on her “So Messy” podcast, which she co-hosts with fellow actress Christina Applegate, who also lives with multiple sclerosis.

Better Understanding of Multiple Sclerosis

Multiple sclerosis (MS) is an “immune‑mediated condition,” meaning the immune system mistakenly attacks the body’s own tissues, explains Dr. Lauren Krupp, a neurologist at NYU Langone.

“We’re not exactly sure why that happens,” she tells SurvivorNet, “but it probably has to do with exposure to a virus at some point. In the effort to fight off that virus, the immune system turns against itself and specifically targets a coating of the nerves called myelin.”

Myelin protects nerve fibers in the central nervous system, which includes the brain and spinal cord. When it’s damaged, communication between the brain and the rest of the body becomes disrupted.

Since MS can affect different areas of the brain or spinal cord, Dr. Krupp notes, “the symptoms can vary in location.”

Common symptoms include:

• Numbness or tingling in the face
• Numbness or weakness in the arms or legs
• Vertigo or a spinning sensation
• Blurred or lost vision
• Poor coordination

Symptoms may appear on one side of the body or, when the spinal cord is involved, on both. Numbness can spread and may be accompanied by muscle weakness.

The National Institute of Neurological Disorders and Stroke describes MS as “an unpredictable disease of the central nervous system” that can range from relatively mild to significantly disabling, depending on how severely communication between the brain and body is affected. Researchers widely consider it an autoimmune disease.

There is currently no cure for MS, but many people manage the condition with medications, steroid treatments, or, in some cases, chemotherapy‑based therapies designed to calm the immune system and slow disease activity.

Dr. Sicotte says advances in MRI technology — along with new imaging biomarkers — are making multiple sclerosis diagnoses far more precise. “MRI is the technique of choice to evaluate folks for MS,” she explains, noting that today’s highly sensitive scanners mean an MS diagnosis essentially requires finding an abnormality on imaging.

Those abnormalities typically appear as bright spots or signal changes in the brain’s white matter, reflecting damage to myelin, the protective coating around nerves. “That is a hallmark of the condition,” she says.

Learning to Live With MS

Common tools M.S. patients use to improve their quality of life include wheelchairs, canes, leg braces, and some medical treatments called disease-modifying therapies (DMTs).

A study in American Family Physician found that DMTs “have been shown to slow disease progression and disability; options include injectable agents, infusions, and oral medications targeting different sites in the inflammatory pathway.”

Research published in Frontiers in Neurology last year says autologous hematopoietic stem cell transplantation (AHSCT) (also called bone marrow transplantation, with autologous meaning a patient’s own cells) used for multiple sclerosis therapy helps “reset the immune system.” Several studies and clinical trials using AHSCT have shown promise.

WATCH: SurvivorNetTV Presents: Defying All Odds – A World-Renowned Doctor’s Incredible Journey Through MS

“In a meta-analysis of published studies using AHSCT for M.S. treatment, the pooled estimated transplant-related mortality was 2.1%, the two-year disease progression rate was 17.1%, the five-year progression rate was 23.3%, and a pooled 83% of patients had no evidence of disease activity at two years. Patients who had the most benefit and the least mortality rate were patients with relapsing-remitting M.S. (RRMS).”

Additional research published by NEJM Journal Watch says that AHSCT helps MS patients reduce relapses better than other forms of MS treatment.

The National Multiple Sclerosis Society outlines the different types of multiple sclerosis:

• Clinically isolated syndrome (CIS) is when an individual experiences a single neurological episode lasting 24 hours or less. CIS is what M.S. is diagnosed as until there is a second episode.
• Relapsing-remitting MS (RRMS): The most common M.S. among the million people battling the disease in the U.S., RRMS is marked by sudden flare-ups, new symptoms, or worsening of symptoms and cognitive function. The condition will then go into remission for some time before reemerging with no known warning signs.
• Primary progressive M.S. (PPMS): These individuals have no flare-ups or remission, just a steady decline with progressively worse symptoms and an increasing loss of cognitive and body functions.
• Secondary progressive M.S. (SPMS): This is an almost transitional form of M.S. that progresses from RRMS to PPMS.

Finding Resources And Support

For patients and families navigating MS or another serious illness like a cancer diagnosis, gaining access to new treatment or trials can feel overwhelming. That’s why SurvivorNet encourages patients to use its proprietary Clinical Trial Finder, a free tool designed to help patients identify relevant trials quickly and easily.

Every year, new early-phase studies come online, each one representing another step forward in disease management.

SurvivorNet’s AI-powered “My Health Questions” tool was also built with patient needs in mind, to give patients and their caregivers access to health information vetted by professionals right when they need it.

Questions for Your Doctor

If you are diagnosed with MS or are concerned you have the chronic disease due to symptoms you’re experiencing, consider asking your doctor the following questions.

• Although there’s no cure for MS, which treatment option do you recommend to manage my symptoms?
• Are there any potential side effects of MS treatment?
• What if the treatment to manage symptoms doesn’t work?
• Will exercise or therapy help my symptoms?
• Are there any MS support groups you recommend to help me cope?

Learn more about SurvivorNet's rigorous medical review process.

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