To describe the natural history of a condition or disease. To describe the natural history of a condition or disease. To determine effectiveness or cost effectiveness of treatments/services and/or health care products. To measure or monitor safety and harm. To measure quality of care.
According to the NMSS, attacks or flare-ups of symptoms only qualify as exacerbations if: 1  they occur at least 30 days from an earlier flare-up. 2  symptoms last for 24 hours or longer.
Call it a flare-up, an exacerbation, an attack, or a relapse. Whatever you call it, it's not something you expect. When you have relapsing-remitting multiple sclerosis (MS), you can go days or years without major changes in your symptoms.