Actor Selma Blair, known for her roles in Cruel Intentions and Hellboy, said in an Instagram post on Saturday evening that she had been diagnosed with multiple sclerosis in August. While Blair only recently learned of her condition, in the post she said she may have been exhibiting symptoms for 15 years.

On Instagram, Blair said that her memory is often foggy, and that she struggles with fatigue and mobility on her left side. Multiple sclerosis is a chronic condition that affects the brain and/or the spinal cord and can cause vision problems, muscle stiffness, balance problems, fatigue, and more.

Blair is currently filming Another Life, a new Netflix series co-starring Katee Sackhoff, about astronauts on a mission to explore the origins of an alien artifact. Blair said she felt empowered to talk openly about her diagnosis because of the help she’s received from Another Life’s costume designer, Allisa Swanson. “The brilliant costumer #Allisaswanson not only designs the pieces #harperglass will wear on this new #Netflix show, but she carefully gets my legs in my pants, pulls my tops over my head, buttons my coats, and offers her shoulder to steady myself. I have #multiplesclerosis.”

Blair thanked a handful of friends and family who have stood by her since her official diagnosis, and said she’s received messages of love and support from them and others who have M.S.—who are thanking Blair for talking about her diagnosis and living with the disease.