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.
Back when I was in basic training they had a blood drive bus come and me and 1 other guy didn't give blood. The drill Sgt tried shaming us be we never broke. Saying soldiers are dieing out in the field because of us. That blood drive profits off that blood and I refuse to give for free for them to profit