Few possibilities. In the young and healthy, feet swelling could mean a blood clot, but usually on one side. Some medications can cause leg swelling. Heart failure, protein manutrition, advanced liver and kidney diseases can do that as well, as does pregnancy etc...Trauma, excessive heat, prolonged standing can cause some swelling too. Some have idiopathic swelling--which mean no known cause. Consult doc. Good luck.
Many things. Swelling of the feet is called pedal edema. It can be caused by several things including kidney failure, heart failure, liver failure. A blood clot in the legs can also cause this problem but it is usually also associated with pain and redness in the legs.
Means you. Should see the doctor to find the etiology...As there are many possibilities.