I have several different types of fibromyalgia flares. Some are straight pain flares... like the aches you would get from the flu and arthritis on massive steroids. The pain flares suck but, believe it or not they are the easier ones to deal with. Take some pain meds and limit my movement for a day or two and I can bounce back with minimal amounts of cursing under my breath when the children bounce off of me.
Then there are what I call SENSORY flares. These suck worse than just about anything on the planet. Anyone who has ever had a bad migraine headache (or even a major hangover) can get a very basic idea of what a sensory flare is like. With a migraine (or killer hangover) your senses of hearing and sight get mega sensitive. Every small sound or bit of light is amplified 10 times its original strength. A slamming door or an overhead light cause intense physical pain... Now take that concept, that ultra-sensitivity, and apply it to ALL your senses at the same time.
I feel like I have some small comprehension of what it must be like to be stuck in an Autistic mind and body because these particular flares often lead me to curl up in a dark quiet room with my eyes squeezed shut and my fingers in my ears hoping to stop the painful sensation overload. My toddler running his fingers across the back of my arm feels like someone has pulled the edge of a hot pan from the oven across my flesh... scalding, searing pain that makes my muscles twitch and jump to escape the touch. Changing a dirty diaper or taking out the trash smells like what I would imagine wading through waist deep raw sewage would.
The only major up side to this type of flare (and talk about searching for a silver lining!) would be the rare opportunity to lock myself alone in a pitch dark and quiet room while letting my highly sensitive taste buds go nuts over bits of dark chocolate melting on my tongue... If only all the overly sensitive stuff could be that good!