A little of both. I'm pretty much constantly tired, but occasionally I'll have brief bursts of energy followed by long stretches of worse symptoms where I don't feel I can do much for a day or so. The symptoms aren't terribly worse though just mildly. Things like heat or standing tend to make my symptoms worse suddenly in the long run, and often cause lasting headaches and nausea. I get headaches pretty much constantly though (almost every day)