To the experts in the house, Help!

My father, aged 60+, has been suffering from prostate cancer since late last year. Around March this year, he went under the knife and the prostrate was removed.

The issue now is that before the surgery, his feet were swollen as it's the usual case of prostate cancer patients. But two months after the surgery, the feet are still swollen and maybe even worse.

Although, the constant pain has reduced as he has been taking his medications faithfully. His doctor friend told him to start moving around to exercise them yet the feet are still swollen.

I'll appreciate if I can get any useful advice as to what to do.

N.B: He can't visit the hospital (Luth) at the moment due to the covid-19 pandemic.