I agree about not wanting to explain why I've been downplaying this for months. My pdoc knows I've had some dizziness and the tachycardia but not the lightheadedness (which has been increasing for a few months). The lightheadedness now needs to be assessed. I can't even walk the dog at a slow rate without gettting lightheaded, much less get the exercise I need. And I've not told anyone because I"m scared I'll have to come off the only med that has been effective. But I also know better than to not tell about something potentially serious. Oh well. My pdoc is very patient thank God.