The implication of aircrews and blood clots is a false inference.

There IS a lack of aircrews causing delays. High altitude isn’t shown to cause blood clots, but the lack of movement DOES show an increase of causing blood clots. Pilots sit at the controls for many hours at a time.

Therefore, No...a lack of aircrews is not because of blood clots.

During the shutdowns some airlines layed-off pilots, and now they must get them trained and current. People don’t understand that pilots are highly regulated and can’t be off flying status that long without having to undergo a review in the simulator.