I was volunteering at the hospital today, and Mr. X was there because of alcohol-related poisoning. The nurse in charge of him was kind enough to let me shadow and help her, while she tried to get some blood samples.  Surprisingly to me however, she couldn’t find a single vein in either of his arms. What? I had heard about veins disappearing after frequent injections, such as in drug use like heroin, but I didn’t realize it was a medical condition.

So, I researched it after I got back and apparently, the veins actually literally disappear in a condition called collapsed veins.  After damage to veins, because of injections and such, blood starts to clot around the damage due to turbulence in blood flow. We all know that. But after frequent damage, the clots start blocking the veins. Once completely blocked, the veins collapse. These veins never recover and hence the disappearance. For visual learners, the diagram below may be helpful.

How veins can collapse (click to enlarge)

Wait! If the vein disappears blood would never get back to the heart, and that should lead to death. Right? Aha! “You have been been well-trained, my young apprentice.”  But, the body figures out another way of routing the blood back to the heart through deeper veins.

I found this really helpful link: How veins collapse. Enjoy!