I can certainly identify with you. I've been on warfarin (blood thinner) for over twenty years now, and need my blood taken on average once a week or once a fortnight if things are stable. When I was diagnosed with the cancer, they put in a port as my veins were, to put it mildly...rather fornicated. Although I still have my port for hospital use, the phlebotomists at the pathology labs are not port certified, and I too only have the one arm that can be used. I go to the same place each time, and insist on the same lady taking my blood. I've had more than a few of Dracula's Brides poking, stabbing and generally stuffing up in the past, and I don't give a toss about hurting their fragile egos. I make sure I'm not dry, and also, while waiting. I keep my right arm dangling straight down so the blood pools in that arm. My lovely lady then rubs my best looking vein in steady strokes from upper arm to fingers. She then palpates the vein with eyes open. Then she closes her eyes and feels ever so carefully the best spot, opens her eyes and then slips in an infant sized butterfly needle. She gets it in first shot every time. Hope some of this info may help.