: the rules vary a bit depending on specifics, but in general, your consent is required for the drawing of blood or any other actual procedures
, while the choice of specific tests
to run with that blood are usually at the discretion of the physician. Running a test on a blood sample to look for a potential disease after an initial blood factor test comes back abnormal is pretty standard procedure. This is particularly true if the illness is question is known to be common in your sex, race, or immediate family background.