How to deal with water retention in feet, ankles, and lower legs?

Edema. Swelling to the feet and ankles is common as we get older. It can be a vascular insufficiency, kidney or blood pressure issue. If you have been given a diuretic by your doctor - take it on schedule! You can try to wear support hose and elevate your fee when out of bed. If this does not relieve your issue see your doctor. Do not ignore this.
See your physician. This could be due to high blood pressure, kidney disorders, heart problems, or poor valve function in your veins. I would recommend seeing your primary care physician first and getting a complete check up.
Water retention. First you must find our why you are retatining water is it renal or cardiovascular then you can treat.