For each of the last fifteen years I've had to have at least one blood draw or other medical need to puncture a vein. (Some years I've had many more than one.) I have had "bad veins" from the start. About once in three or four times, the person sticking me gains access on the first attempt. And most of those are almost painless. The rest of the time, I have to have multiple sticks, and they usually sting. (I understand there are far, far worse procedures; this is more a question than a complaint.)
My two, related questions are: why are my veins "bad" and why is tapping them sometimes extremely easy but most times quite difficult? This is prompted by my visit last week to Duke University Medical Center, generally a fine place, but at which I had four--four--people work for about 20 minutes trying to get an IV in.
Over the years, various folks have offered three theories about why I'm usually hard to stick: 1) I'm fat, 2) my blood sugar must be too high, and 3) I might not be sufficiently hydrated. But strong evidence against all three theories, at least to me, is that I've had several instances of one stick-er having difficulty, or failing completely, only to be followed by a different person, mere minutes later, succeeding.
I conclude that the skill levels of the people involved must vary substantially, but I would be interested in other theories or information. Also, if anybody can point me to a clear explanation of how best to stick a person with bad veins, I'd appreciate it. I've looked briefly on the Web, and to my surprise, I didn't find much.