Given your history and present symptoms, I believe that the most important entity to consider now and
eventually rule out is the possibility of a venous thrombosis. This can be an unusual side effect of your
hypertension medication, or can be due to idiopathic causes. This is characterized by obstruction of the
veins impeding venous return from the involved extremity.
This would be manifested as tension, erythema and pain of the involved arm or leg.
I suggest you have this seen by your doctor and possibly run some tests such as venous doppler studies to
facilitate evaluation of the venous drainage.