With multiple sclerosis (MS), you'll have good days and bad days. You might feel fine for weeks or months, and then your symptoms suddenly get worse.
Days when your old symptoms pop up again or new symptoms start are called relapses, attacks, or flare-ups. Everyone's flare-ups are different. Some are mild. Others are severe.
The goal is to prevent relapses. When your symptoms do get worse, know how to treat them so you can feel better faster.