In an Instagram post Saturday, the "Cruel Intentions" actress revealed she was diagnosed in August, and is facing the effects of the disease everyday. "I am disabled. I fall sometimes. I drop things," she posted. " My memory is foggy. And my left side is asking for directions from a broken gps. But we are doing it. And I laugh and I don't know exactly what I will do precisely but I will do my best."Multiple sclerosis is a neurological disease that occurs when there's a breakdown in communication between the brain and other parts of the body, according to the National Institutes of Health. Symptoms include blurred vision, and difficulty with coordination and balance. Multiple sclerosis affects 400,000 people in the United States and 2.1 million people worldwide, the NIH says. Blair, 46, said she's had symptoms for years, and thanked her producers at Netflix for being understanding. She said she hopes "to give some hope to others. And even to myself," and encourage people to ask for help when they need it. "I have probably had this incurable disease for 15 years at least. And I am relieved to at least know," she posted.Blair has appeared in films and TV shows such as "Legally Blonde" and FX comedy "Anger Management."Several celebrities have revealed they have multiple sclerosis, including TV personality Jack Osbourne, talk show host Montel Williams and "Sopranos" actress Jamie-Lynn Sigler.