Yes it can be from the feet job. But the way you are describing it You can either have a stress fracture in your foot which sometimes won't cause pain so you won't even realize until the swelling in it and it could also be a blood clot in your lower leg which in turn is causing your ankle and foot to swell. My recommendations to you is to get an x-ray done on it right away to rule out stress fracture and get an ultrasound on your ankle/foot to rule out the clot. You can try an ace wrap to reduce swelling along with ice for 20mins on and 20mins off and also elevating. I would recommend to call your doctor to get this taken care of or you are likely to damage tendons and ligaments in your ankle/foot and would need definite surgery. If I can be of further assistance or you have further questions please don't hesitate to ask. Best regards and good luck, Dr. Bonnie Lenzenhuber MD