I have had a couple of friends attempt to donate blood recently who were turned away because the machines weren’t able to draw from them.
Tubing issues were blamed first.
Eventually, the staff told them they couldn’t donate because the flow was being blocked by clots.
In both arms.
These people are all under the age of 35, by the way. And were under the impression they had no health issues.
If the blood flow in both arms is blocked by clots - how are these people still up and walking around and feeling fine?
I honestly don’t know, other than maybe the clots are big enough to affect tubing, but not big enough yet to cause a heart attack or stroke?