I took me a while to realise this only happens to me when I'm already anxious at rest. I said this to my therapist yesterday and she already knows this happens while suffering with anxiety, it took me 2 years to realise this.. 

When I stand up after feeling really anxious nausea, butterflies in stomach, flushed face, heart pounding etc. my heart will either skip, pound or race when I stand up. I notice too if I'm really anxious and try to go on a walk my heart rate goes really fast too and pounds. My cousin told me this used to happen to her when her health anxiety was really bad.. I thought I was the only one. DOA feel this too?