I do suffer from muscle fatigue after exertion and general exhaustion after some days at work, it seems to build up. But this is a bit different to that feeling I can struggle upstairs, I can climb steadily upstairs and I can get this wierd overwhelming weak feeling after climbing stairs and all this can happen in a morning. My fatigue appears to increase over time, my weakness appears to be episodic and brought on by different things, mostly to do with climbing. Trouble is I have been tested for myasthenia gravis,negative, and other neuromuscular conditions, including negative muscle biopsy (apparently it was virtually normal), and the last strength test was normal. I never have any tests while actually suffering from the fatigue or weakness, do you think this would make any difference?