OK, apparently I have very low potassium. Some of the symptoms include fatigue, muscle cramps and abnormal heart rhythms. Yikes. But might also explain why I've been feeling so low energy and lethargic recently. At my last doctor's visit, I was told to try increasing my dose of potassium supplement. I've done so over the last few weeks, and went in today to get some follow-up blood work done. And then this evening I got a call by the covering doctor to tell me that low potassium is still an issue and that it needs to be addressed. That can't be good. It may just be a simple case of changing my blood pressure medication - I use a diuretic and that is likely to be the cause of the issue. But we shall see. It seems like I have the joys of trying out different blood pressure medications, and their associated side effects, to look forward to again. Great.