I'm a little confused over what POTS is, exactly. I know there's the blood-pressure/heart-rate changes on standing, which would presumably cause dizziness etc. However, I have these symptoms and was wondering if they fit at all: 1. Extreme physical weakness (like my limbs are heavy/made of stone); also, some loss of coordination and difficulty walking. Moving my body becomes a burden. 2. A feeling that I'm sinking into the ground when I walk, or being pulled down by gravity. 3. Difficulty standing (but also because of the weakness + the sinking feeling). 4. Constant adrenaline. 5. Breathlessness/faintness on exertion (running up stairs). The symptoms are worse when I haven't eaten, and are also improved sometimes by salt/hydration. Interestingly, when my 'adrenals' respond temporarily to things (caffeine, herbs etc.) before tolerance sets in, a lot of these symptoms improve.