What might elevated PTs and PTTs mean in the absence of any other
blood-related anomalies, use of medications, etc? What problems would have
to be ruled out? Thanks in advance.

robert

By blood-related anomalies what do you mean?
All other coagulation tests normal such as D-Dimer?
First you need to do a mixing study to determine if there are factor
deficiencies or circulating anticoagulants.
That test is called a 1:1 mix PT and or PTT. It can tell based on the
correction studies which is the case.
The age of the person is important as is a physical exam.
Among the factor deficient category is decreased production due to liver
disease or a consumption coagulopathy. You also have the malaborption
people in here also as vitamin K is produced in the gut and is needed in the
production of coagulation factor.
To check for coagulation factor consumption a FDP or fibrin degradation
product test may be performed. It can be used to detect clot formation in
the body as in Pulmonary embolism.
For circulating anticoagulants you have acquired anticoagulants such as
Anti-phospholipid syndrome, the so called lupus anticoagulant and some
cancer associated heparin like anticoagulants. There are other test to
confirm these also.
By far the most common are acquired factor deficiency ones.