Retired medical doctor, Dr Vernon Coleman, describes Coleman's 1st Law of Medicine: If you're receiving treatment and you develop new symptoms you should assume they're caused by the treatment you are receiving.
https://www.youtube.com/watch?v=b3mKzVU7bVI
Coleman's 2nd Law of Medicine: Tests are useless unless the Results will affect your Treatment.
5mins, pertinent to what's going on with COVID testing, and the current state of medicine.
https://www.youtube.com/watch?v=Jj7FNgKYf8o
"…doctors treat the test, not you (the patient)"