Swelling in Lower Extremities

Lately, for the past 4-6 weeks, I have been having swelling in my ankles and sometimes lower legs.  Especially noted when i have been sitting for long periods of time during the day, as I am in a job that requires me to ride a desk almost all day.  I have BPH and take Proscar and Cardura, as well as taking Norvasc for hypertension.  Anysuggestions on the causes and possible remedies?  Could the meds be having any effect?

Thanks in advance.

P