Initial testing is usually performed to determine if a person
has or has had a blood clot (thrombotic episode) and, if so, to
help determine the person's risk of a repeat thrombotic episode.
Although it may be fairly simple to identify that a person has a
clot, identification of the underlying cause may take more time
and effort. This is because several of the diagnostic tests that
need to be done are affected by an existing or recent blood clot
and by any anticoagulant therapy that is given. Often, the
doctor may have to order a few tests and treat the person's
existing blood clot first. Several weeks or months later, when
he is able to take the person off of anticoagulant therapy, the
doctor can order other tests to finish his evaluation of the
cause of the clotting. Follow-up testing is important in helping
to determine a person's risk of developing recurrent blood
clots. The table below lists some of the tests in alphabetical
order. For detailed information about each test, click on the
name of the test t