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.
There is no easy answer to your question about flare-ups. Every single person who has MS experiences it differently, and every incidence that each person experience can be different from the last. I have had MS for 21 years. In that time I have had numerous exacerbations and a wide range of symptoms.