In the 2024 survey of 375 women with MS, more than 85% reported that MS symptoms worsen during the menstrual cycle, with more fatigue, pain, cognitive changes and muscle weakness. Most responders said it becomes harder to work, take care of kids, do chores and socialize. This survey was conducted on behalf of the International Advisory Committee on Clinical Trials in Multiple Sclerosis, which is jointly supported by the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) and the U.S. National Multiple Sclerosis Society.Rousseau, who is a schoolteacher and cross-country coach, confirms that having her period affects how well she can teach and support her husband and five dogs at home. It kicks off with a vicious migraine, then she becomes completely drained. “People say, ‘Oh yeah, I get tired, too’ — but they’ve never felt MS menstrual fatigue,” she says. Her heat intolerance increases as well, compromising her balance on her bike.Although studies point to worsening motor symptoms, vision problems and altered coordination in the three days leading up to your period, plus dips in mental sharpness around the time your period is due, your symptoms will reflect your individual experience of MS.“Generally, whatever symptoms someone with MS has, those symptoms get worse,” says Maria Houtchens, MD, associate professor of neurology at Harvard Medical School and director of clinical care at the Brigham MS Center.“Just like many people feel crummy, with more fatigue, mood changes and sleep problems right before their period starts,” she adds, “sensory symptoms, pain and spasticity can worsen for people with MS.”Although these symptoms — especially fatigue, weakness and pain — can mimic an MS flare, that’s not what’s happening. “Menstruation affects the symptoms that MS causes,” Houtchens says, “not the disease itself.”
