@tootyfruitypickle
Here's some digestible science on it:
www.nature.com/articles/d41586-020-01403-8
Basically anyone who is prolonged immobilised (in bed sick) is at an increased risk of clots irrespective of COVID, but this thing called the ACE2 receptor protein is key as that's basically how COVID gets in the cells. It's interesting the tiny clots might be the reason for low oxygen.
There's a lot of research going on around ACE2 as this was known already.
Anti-coags taken preventatively are not yet recommended for all COVID patients.