I think it is a matter of what the doctors can track, which is obviously not the same as what the patient experiences over time. Since it is not understood what causes
fibro or what damage it causes
, the effects of fibro can not be measured or monitored with time. Therefore, it is said to not be progressive. However, as you can read from patient testimonials, the day-to-day symtpoms and quality of life can be affected in a way that worsens over time.