Welcome to HCM,
After going through your history you have high blood pressure
and taking treatment for it, this is good that your blood pressure is well controlled,please continue to take your medicine regularly.
Your swelling over legs is dependant edema so it should be examined by Physician and relevant investigations about cardiac cause by ECG,Echocardiography
, blood test like complete blood count
,Liver function test.and kidney function test.Treatment depends on cause.
You have not mentioned about your weight as knee pain could be some kind of arthritis commonly Osteoarthrosis
affects the weight bearing joint like knee.
Get an X Ray of knee and consult Orthopedic surgeon if necessary MRI of knee joint will detect the cause and further action depends on result of tests.
Please take care.
Dr.Akhilesh Dubey M.D.