I have already answered your question, below is the copy of that answer.
Thank you Melanie, for posting the question again. the knots can be a sign of varicose veins, which become more painful when you stand up due to pooling of blood in those veins because of the action of gravity. This can also be a contributing factor or a cause of the swelling of feet and ankles. Varicose vein is a condition in which there is swelling superficial veins of the lower leg due to the insufficiency of venous valves, this condition is more common in females. Have yourself examined by a general surgeon or a family physician. Moreover other causes of swelling of the bilateral feet include, lymphatic insufficiency, a heart problem, a liver problem, a kidney problem or deficiency of some nutrients. So we have to rule these out one by one. Please have an appointment with a doctor so that the cause of this swelling can be found, once the cause is found, specific treatment will lead to the permanent cure. If you have any further question don’t hesitate to ask.

Best Regards.
Dr. Adil Ramzan