Hello and welcome to HCM. Thank you for posting your question here. I went through your concern in depth. Long standing hypertension or the antihypertensives you are taking can be the cause of your problem. In chronic hypertension due to the increased work load on your heart ,the pumping mechanism of your heart may become progressively less effective and it can cause pooling of blood in the blood vessels of legs.Fluid may then leak into your adjacent tissues from this pooled blood and cause oedema(fluid collection in tissues). Antihypertensives can also cause this fluid buildup,especially antihypertensives called calcium channel blockers.These drugs causes the blood vessels to dilate or open wider and may lead to fluid leakage. So to make an accurate diagnosis,I need to know a few more things like the specific antihypertensive you are taking, how long you had hypertension, do you have any kidney or liver disease,if you have oedema or fluid buildup in other parts of your body. If you were my patient ,depending upon the cause i will either reduce the dose of antihypertensive and add a diuretic to reduce fluid retention or add another antihypertensive to control your blood pressure more effectively. So I advise you to consult with your doctor for further evaluation and to make any necessary changes. You should sit and sleep with your legs elevated, do some mild to moderate excercises, avoid prolonged sitting to reduce the fluid buildup. I hope i have helped. Thank you.