Hi welcome to the health care magic Here you might have kidney affection leading swelling in feet... Kidney nephropathy, diabetes nephropathy, nephritis (if hypertension and oligouria present) etc like causes has to be ruled out For that USG done and if needed biopsy can be done for further work up only if needed According to cause specific treatment given If needed Urine culture done to rule out lower urinary tract infection Cardiac causes, liver affection, hypoproteinemia etc ruled out if no cause for edema found Take care Consult physician for examination and accordingly your management plan decided Hope your concern solved