EDS is ehlers danlos syndrome. It is a genetic problem that causes dysfunction of the collagen in the body. I was diagnosed with type III also called joint hypermobility syndrome ( my joints overextend without any pain). The collagen problem causes the blood vessels to be weak and over strech. When you stand up your blood vessels should constrict to circulate the blood. My blood vessels are too week and I get blood pooling and low blood pressure - dizzyness, etc. The blood vessels cannot overcome the force of gravity pulling the blood down. Likewise, if I hold my hand up the air - my hand turns white and cold because all the blood runs right out. www.ednf.org ehlers danlos national foundation www.ceda.ca Canadian ehlers danlos association I am still learning about EDS. If someone wants to add more please do so.