11charlie

Looks like you could have venous tos. It is bad with your arm down because blood is flowing through the artery down the arm and when it starts to return through the vein it can’t return blood flow to your heart due to venous compression. Generally a tight pec minor, tight subclavius, elevated first rib, depressed clavicle or rarely a blood clot can cause this occlusion. It’s better with your arm up because the blood isn’t flowing down the arm therefore venous return is negligible. The fatigue could be caused from blood flow not getting back to the heart from the arm. A vascular surgeon can diagnose venous tos.