Fibromyalgia is very much a rollercoaster ride that you cannot get off of. You are very tempted on the days you feel less pain to get a whole lot done, which will cause you even more pain the next day, if not more than that. So resisting that temptation is a good thing. Saves some of that rollercoaster ride of pain if we stay within our limitations and moderate our activities all the time. Although then we never feel like we are ever accomplishing anything. For example, I can never ever just clean the house. That is an impossible feat. On a good pain day I can do the tasks that are more difficult like vacuuming or cleaning the bathtub and on real bad days I can just tidy up a bit and call it a day. But you always have to segment your activities and so you never feel like anything is really ever getting done. However, my spouse does help with some things... like he does all the shopping. So that is a massive help to me. That has always been a task that I have found to be quite draining.
It is easy to see how people might not comprehend the extend of fibromyalgia and its impact though because of the fact it is invisible and appears to fluctuate so much. We are always tired and we are always in pain, but the amount of that varies and the amount we can function can vary too. So, yes, we can go from great to completely non-functional at the drop of a hat. That is the way this works. Especially if we push ourselves.
And it is not the same level of functioning all the time. There are times when I can walk a good distance and experience moderate pain while doing so before the pain gets too much for me. Other times I cannot even walk ten minutes before the pain is extreme and I end up walking extremely slow to compensate for it until I can get to someplace I can rest because the pain just gets worse and worse until I do. And there is absolutely no way for me to predict which reaction my body will have to walking on any given day. All I do know is that standing for any length of time or sitting in any position for too long will definitely be painful, so I must alternate and change positions a great deal.
And I cannot predict flare ups of pain that are not due to weather or overexertion either. Sometimes pain flares up extremely in a specific muscle group or skin nerve pain for no particular reason. Sometimes severe foot pain in the arch, sometimes severe wrist pain. Recently severe skin pain that I believe was triggered either by a migraine or a sinus cold. These flare ups are pretty extreme in level of pain and the duration can vary widely from a day, a week to much longer.
And of course with any chronic illness there is the fatigue component added in there. Fatigue with a capital F. And that is pretty hard to cope with to be honest.