What is an AVM, or Arterio-Venous Malformation?
Put simply, an AVM is a tangle of tiny veins which makes it more difficult for blood from the arteries to eventually make their way to the veins. Oxygen-rich blood goes down your arteries from your heart and lungs, they channel off into smaller branches, those branches have even smaller branches, this goes on till the blood passes through tiny capillaries – their aim is to nourish tissue. When the oxygen is taken out of the blood, it needs to make its way back to your heart, through tiny vein capillaries, into larger veins and back to your heart and lungs. A tangle of tiny veins which block this process is called an AVM. Imagine a ball of yarn with many knots, with threads coming out of it in several directions. As you pull at the threads, the center of the yarn gradually tightens. The tangle of veins will tighten in the same way the center of the yarn does, if blood finds it harder to get through the vessels and they start to swell. Eventually, you have a tight ball in the center, the
