What makes hypotension more sympathetic? a drop in systolic pressure, a drop in diastolic pressure, or a drop in mean arterial pressure? how long is too long for prolonged hypotension? how low is too low a bp to self treat at home?

Not sure what you mean by sympathetic. Essentially, if you are noticing that you are feeling weak, dizzy when you stand up, or lightheaded, then you should have your blood pressure evaluated regardless of whatever number it is. You should see your primary care doctor for further evaluation. Good luck.

If you get dizzy see someone. Treat how you are feeling doing and not the BP.