My best friend and I, and my mom....same thing!!! my sister has had issues with her neck ... there's no injury reasons and she's a stay at home caretaker for her husband who had a partial stroke about 4 years ago.... so it's nothing SHE did!!
I saw a documentary where numerous doctors from all over the world have been finding, keeping, studying these "worm-like things" in peoples veins!! No explanations. They're all very perplexed. Google that!! It's creepy!!