Fighting Against Gravity

Yesterday I mentioned that my body does not counteract gravity very well. Today I would like to tell you a little about my fight against gravity.
In a healthy person, blood vessels constrict when the person sits or stands. This vasoconstriction counteracts gravity and keeps blood flowing back up to the heart, lungs, and brain. Because I have dysautonomia, my blood vessels do not constrict well when I am upright. This means the longer I am upright, the more blood I have pooling in the lower hal...